New Technique required beyond quantum Transport
For Topo Insulators, đđ„đŠ (Transport) = 0; all 4 âTopo Invariantsâ that define them must be measured via Spectroscopy probing Bulk-Boundary correspondence directly :
See, Review, Hasan-Kane RMP 82, 3045 (2010)
APS-Physics lecture: https://absuploads.aps.org/presentation.cfm?pid=14503
This (đ(Hall) = 0) leads to New Physics: Beyond all forms of quantum Hall paradigm ..
https://iopscience.iop.org/article/10.1088/0031-8949/2015/T164/014001/meta
Materials are not new - existed long before..
New Physics enabled by New Techniques
Materials existed long, long before .. (Materials are not new!)
What is new?
Advanced Spectroscopic experiments that enable precise determination of âTopological Invariantsâ (see, for a review, RMP 82, 3045 (2010)
New Methods ...
Lab Theme: Fundamental Physics of Quantum Matter
Hasan group research is focused on exploring novel physics of quantum-many-body emergence, correlated electron motion, Bose-Einstein condensates, quantum coherence, and topological (weakly or strongly interacting, quantum entangled, topology and entanglement) emergence by combining novel Spectroscopy, Microscopy and Transport methods as well as Theory (funded by multiple grant agencies). We are funded for THEORY by multiple grant agencies.
Unlike string theory, topological physics in lower dimensional condensed matter systems is an experimental reality since the bulk-boundary correspondence can be probed experimentally in lower dimensions. Recent experimental discoveries of non-quantum-Hall-like topological insulators, topological superconductors, Weyl semimetals and other topological states of matter also signal a clear departure from the quantum-Hall-effect-like transport paradigm that has dominated the field since the 1980s. It is these new forms of matter that enabled realizations of topological-Dirac, Weyl cones, helical-Cooper-pairs, Fermi-arc-quasiparticles and other emergent phenomena in fine-tuned photoemission experiments since such experiments directly allow the study of band-inversion, spin-texture imaging, spin-momentum locking, bulk-boundary (topological) correspondence. Taken collectively, we argue in favor of the emergence of âtopological-condensed-matter-physicsâ in laboratory experiments for which a variety of theoretical concepts over the last 90 years (Dirac-Weyl topology, negative-Dirac-mass, Dirac-monopole-Berry charge, Aharonov-Bohm phase, C.Herring's exceptional points (modern Weyl node), Karplus-Luttinger theory (modern Berry curvature), SSH-chain, Jakiw-Rebbi and many foundational theories before and around 1970s â most topological theories are not new.. ) paved the way for modern experiments on Topological Materials! (Materials are not new either)
What is new? Advanced Spectroscopic experiments that enable precise determination of âTopological Invariantsâ (see, for a review, RMP 82, 3045 (2010)
APS-Physics: "Topological Invariants via Spectroscopy (New Methods)"
Topo Invariants precisely define a New Topo State of Matter which can be precisely measured via Spectroscopic measurements (no transport or quantum Hall transport is needed). This invited talk at APS-Physics elaborates this NEW method which enabled discovery of many NEW topological states of matterâŠ
Text Book Inclusion :
Textbook inclusion of Experimental Results from our Lab : A few of our results, including Topological Insulators and Weyl-Dirac Semimetals, are now included in many standard textbooks of condensed matter physics [see, for example, âModern Condensed Matter Physicsâ by K. Yang and Steven Girvin (Yale University) ]
Our method of using advanced SPECTROSCOPIC techniques as novel methods to directly measure topological invariants in old and New Classes of quantum materials is now taught in text books world-wide.
New âTopo Invariantsâ must be measured via Spectroscopy
For Topo Insulators, đđ„đŠ (Transport) = 0; all 4 âTopo Invariantsâ that define them must be measured via Spectroscopy
See, Review, Hasan-Kane RMP 82, 3045 (2010)
Fermi-Arcs: Discovery of Fermi-Arc (Dirac-string) states in Topo Metals..
Fermi-Arcs: Discovery of Fermi-Arc (Dirac-string) states in Topo Metals..
Science (2014)
A New Paradigm : A Novel Method (Rev. of Mod. Phys. 82, 3045, 2010) for decisively measuring "Topological Invariants"
A New Paradigm : A Novel Method (Rev. of Mod. Phys. 82, 3045, 2010) for decisively measuring "Topological Invariants"
A New Paradigm : A Novel Method (see, invited review, RMP 82, 3045, 2010) for decisively measuring "topological invariants" which led to the creation of a new continent of research (the field of topological materials) with multiple groundbreaking discoveries, including topo. Dirac-Weyl fermions, Fermi arc and more..
https://journals.aps.org/rmp/abstract/10.1103/RevModPhys.82.3045
Theoretical Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class (Bi2Se3 class) with spin-polarized single-Dirac-cone on the surface
Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class (Bi2Se3 class) with spin-polarized single-Dirac-cone on the surface
Theoretical Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class (Bi2Se3 class) with spin-polarized single-Dirac-cone on the surface
A Paradigm Shift..
For Topo Insulators, đđ„đŠ (Transport) = 0; all 4 âTopo Invariantsâ that define them must be measured via Spectroscopy probing Bulk-Boundary correspondence directly :
See, Review, Hasan-Kane RMP 82, 3045 (2010)
APS-Physics lecture: https://absuploads.aps.org/presentation.cfm?pid=14503
This (đ(Hall) = 0) leads to New Physics: Beyond all forms of quantum-Hall-like physics and their modern descendants
âTopological Invariants measured precisely and decisively without resorting to transport methodsâ RMP 82, 3045 (2010))
â.. A paradigm shift in quantum materials research achieved through a new method to measure topological invariants precisely beyond old quantum Hall paradigmâ (for details see, âTopological Invariants measured precisely and decisively without resorting to transport methodsâ RMP 82, 3045 (2010))
APS-Physics: Topological Invariants via Advanced Spectroscopy in New Topological Phases of matter
âTopological Invariants measured precisely and decisively without resorting to transport methodsâ RMP 82, 3045 (2010))
APS-Physics: Lecture Slides : https://absuploads.aps.org/presentation.cfm?pid=14503
Spectroscopic measurement of Topological Invariants (w/o measuring Hall transport)
Intrinsic fully bulk INSULATING 3D-Topo-Insulators (Nature Physics 2014)
Intrinsic fully bulk INSULATING 3D-Topo-Insulators (Nature Physics 2014)
https://online.kitp.ucsb.edu/online/lsmatter_c15/hasan/oh/17.html
Text Book Inclusion :
Textbook inclusion of Experimental Results from our Lab : A few of our results, including Topological Insulators and Weyl-Dirac Semimetals, are now included in many standard textbooks of condensed matter physics [see, for example, âModern Condensed Matter Physicsâ by K. Yang and Steven Girvin (Yale University) ]
Our method of using advanced SPECTROSCOPIC techniques as novel methods to directly measure topological invariants in old and New Classes of quantum materials is now taught in text books world-wide.
Non-QuantumHall-like Topo Materials
Non-QuantumHall-like Topological Matter configuration options
Hasan, M. Z., Xu, S.-Y. & Bian, G.
Topological insulators, topological superconductors and Weyl fermion semimetals: discoveries, perspectives and outlooks.
Phys. Scr. 2015, 014001 (2015).
â.. recent experimental discoveries of non-quantum-Hall-like topological insulators, topological superconductors, Weyl semimetals and other topological states of matter also signal a clear departure from the quantum-Hall-effect-like transport paradigm that has dominated the field since the 1980s. It is these new forms of matter that enabled realizations of topological-Dirac, Weyl cones, helical-Cooper-pairs, Fermi-arc-quasiparticles and other emergent phenomena in fine-tuned photoemission (ARPES) experiments since ARPES experiments directly allow the study of bulk-boundary (topological) correspondence. In this proceeding we provide a brief overview of the key experiments and discuss our perspectives regarding the new research frontiers enabled by these experiments. Taken collectively, we argue in favor of the emergence of 'topological-condensed-matter-physics' in laboratory experiments...â (Non-QuantumHall-like Topological Matter)
Quantum-Hall-like Topological Matter are described by Chern (or âfractional Chern numbersâ) with or without magnetic fields.
Our primary focus is on new states of matter (Non-Quantum Hall-like topological matter).
Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class (Bi2Se3 class) with spin-polarized single-Dirac-cone on the surface
Theoretical Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class (Bi2Se3 class) with spin-polarized single-Dirac-cone on the surface
A New Paradigm : A Novel Method (see, invited review, Rev. of Mod. Phys. 82, 3045, 2010) for decisively measuring "topological invariants"
Fermi-Arcs: Discovery of Fermi-Arc (Dirac-string) states in Topo Metals..
Fermi-Arcs: Discovery of Fermi-Arc (Dirac-string) states in Topo Metals..
Science (2014)
Unexpected and unpredicted novel (many-body, correlated) quantum phenomena in Topological Kagome Magnets & Superconductors:
Unexpected and unpredicted novel (many-body, correlated) quantum phenomena in Topological Kagome Magnets & Superconductors:
Experiments started in 2017, completed in 2017, Natureâ18, NaturePhysâ19, PRLâ19, PRLâ20, NatureComâ20a, NatureComâ20b, NatureComâ20c, Natureâ20, NatureMatâ21, PRLâ21, Scienceâ19, Natureâ19, Natureâ22a, Natureâ22b, PRLâ22, NaturePhysâ22, NatureComâ22, NatureComâ23a, NatureComâ23b, NaturePhysâ23, NatureComâ24a, NatureComâ24b, NatureComâ24c, NatureMatâ24
Novel quantum phenomena in Topological kagome magnets and superconductors (Nature 2022) :
New Phases of Matter: Topological Matter in Lab (2004-2007, KITP 2007, Nature 2008, submitted 2007)
New Phases of Matter Beyond Quantum Hall Physics : Topological Matter in Lab (2004-2007, KITP 2007, Nature 2008, submitted 2007)
KITP Proceeding : https://www.on.kitp.ucsb.edu/online/motterials07/hasan/
2007 KITP Proceeding (Discovery of Topological Surface States in 3DTI)
Experimental Work between 2004-2007, paper submitted in 2007
2007: âTopological Quantum Matterâ, âTopological Spin-Texturesâ and âTopological Dirac Insulatorâ
Hasan and his team coined the terms âTopological Quantum Matterâ, âTopological Spin-Texturesâ and âTopological Dirac Insulatorâ in 2007.
Hasan team demonstrated methods to measure topological matter without measuring transport. Previous methods were based on Hall transport which is a century-old method of measuring topology. It is this new method of measuring topological invariant that lead to a new experimental revolution in the field.
Opening new vistas: .. field-creation..
For Topo Insulators, đđ„đŠ (Transport) = 0; all 4 âTopo Invariantsâ that define them must be measured via Spectroscopy
For Topo Insulators, đđ„đŠ (Transport) = 0; all 4 âTopo Invariantsâ that define them must be measured via Spectroscopy
See, Review, Hasan-Kane RMP 82, 3045 (2010)
https://journals.aps.org/rmp/abstract/10.1103/RevModPhys.82.3045
Intrinsic fully bulk INSULATING 3D-Topo-Insulators (Nature Physics 2014)
Intrinsic fully bulk INSULATING 3D-Topo-Insulators (Nature Physics 2014)
https://online.kitp.ucsb.edu/online/lsmatter_c15/hasan/oh/17.html
APS-Physics: "Topological Invariants via Spectroscopy (New Methods)
APS-Physics: "Topological Invariants via Spectroscopy (New Methods)
Topo Invariants precisely define a New Topo State of Matter which can be precisely measured via Spectroscopic measurements (no transport or quantum Hall transport is needed). This invited talk at APS-Physics elaborates this NEW method which enabled discovery of many novel topological states of matterâŠ
KITP Lecture link .. https://www.on.kitp.ucsb.edu/online/lowdim09/hasan/oh/01.html
KITP Lecture link ..
https://www.on.kitp.ucsb.edu/online/lowdim09/hasan/oh/01.html
Unexpected and unpredicted novel (many-body, correlated) quantum phenomena in Topological Kagome Magnets & Superconductors:
Unexpected and unpredicted novel (many-body, correlated) quantum phenomena in Topological Kagome Magnets & Superconductors:
Experiments started in 2017, completed in 2017, Natureâ18, NaturePhysâ19, PRLâ19, PRLâ20, NatureComâ20a, NatureComâ20b, NatureComâ20c, Natureâ20, NatureMatâ21, PRLâ21, Scienceâ19, Natureâ19, Natureâ22a, Natureâ22b, PRLâ22, NaturePhysâ22, NatureComâ22, NatureComâ23a, NatureComâ23b, NaturePhysâ23, NatureComâ24a, NatureComâ24b, NatureComâ24c, NatureMatâ24
Novel quantum phenomena in Topological kagome magnets and superconductors : https://www.nature.com/articles/s41586-022-05516-0
Fermi-Arcs: Discovery of Fermi-Arc (Dirac-string) states in Topo Metals..
Fermi-Arcs: Discovery of Fermi-Arc (Dirac-string) states in Topo Metals..
Science (2014)
A New Paradigm : A Novel Method (Rev. of Mod. Phys. 82, 3045, 2010) for decisively measuring "Topological Invariants"
A New Paradigm : A Novel Method (Rev. of Mod. Phys. 82, 3045, 2010) for decisively measuring "Topological Invariants"
A New Paradigm : A Novel Method (see, invited review, RMP 82, 3045, 2010) for decisively measuring "topological invariants" which led to the creation of a new continent of research (the field of topological materials) with multiple groundbreaking discoveries, including topo. Dirac-Weyl fermions, Fermi arc and more..
https://journals.aps.org/rmp/abstract/10.1103/RevModPhys.82.3045
Theoretical Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class (Bi2Se3 class) with spin-polarized single-Dirac-cone on the surface
Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class (Bi2Se3 class) with spin-polarized single-Dirac-cone on the surface
Theoretical Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class (Bi2Se3 class) with spin-polarized single-Dirac-cone on the surface
Text Book Inclusion :
Textbook inclusion of Experimental Results from our Lab : A few of our results, including Topological Insulators and Weyl-Dirac Semimetals, are now included in many standard textbooks of condensed matter physics [see, for example, âModern Condensed Matter Physicsâ by K. Yang and Steven Girvin (Yale University) ]
Our method of using advanced SPECTROSCOPIC techniques as novel methods to directly measure topological invariants in old and New Classes of quantum materials is now taught in text books world-wide.
Early works on 3D-TI ..
Hasan group's Theoretical Predictions of Topological Materials
A vast majority of our experimental works are based on our groupâs own theoretical predictions of topological materials (see, for example) :
Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class (Bi2Se3 class) with spin-polarized single-Dirac-cone on the surface
https://arxiv.org/abs/0908.3513 (2009)
(Theoretical Prediction of Weyl semimetals in 2012)
"Topological Electronic Structure and WEYL Semimetal in the TlBiSe Class,"
Physical Review B 86, 115208 (2012).
"New Type of Weyl Semimetal with Quadratic Double Weyl Fermions,"
Proc. Natl. Acad. Sci. 113, 1180 (2015).
"A Weyl Fermion Semimetal with Surface Fermi Arcs in the Transition Metal Mono-pnictide TaAs Class,"
Nature Commun. 6:7373 (2015).
"Room-temperature Magnetic Weyl Semimetal and Nodal Line Semimetal States in Co2TiX (X=Si, Ge, or Sn),"
https://www.arxiv.org/pdf/1604.02124v1 (2016)
"Theoretical Prediction of Magnetic Weyl Semimetal States in the R-Al-X Family of Compounds" Physical Review B 97, 041104 (2018)
(Theoretical Prediction of ) Topological Hopf and Chain Link Semimetal States and Their Applications
Physical Review Letters 119, 156401 (2017)
(Theoretical Prediction of ) "Topological Quantum Properties of Weyl Chiral Crystals,"
Nature Materials 17, 978-985 (2018).
Discovery of 2D & 3D Topological Magnets :
Discovery of 2D & 3D Topological Magnets :
Theory and Experiments : âIn this talk I present our* theoretical and experimental works on 2D and 3D topological magnets in novel Weyl and Dirac materials building up on earlier result but including recent results "A three-dimensional magnetic topological phase" Ilya Belopolski et.al., arXiv:1712.09992 (2017); "Topological quantum properties of chiral crystals" Guoqing Chang et.al., Nature Materials (2018); "Topological Hopf and Chain Link Semimetal States and Their Application to Co2MnGa" Physical Review Letters 119, 156401 (2017); "Magnetic Weyl fermion semimetals in the R-AlGe family of compounds" Physical Review B (2018) and Jiaxin Yin, Songtian Zhang et.al., "Giant and anisotropic many-body spinâorbit tunability in a strongly correlated kagome magnet" NATURE 562, 91â95 (2018). *Guoqing Chang, Bahadur Singh, Su-Yang Xu, Guang Bian, Shin-Ming Huang, Chuang-Han Hsu, Ilya Belopolski, Nasser Alidoust, Daniel S Sanchez, Hao Zheng, Hong Lu, Xiao Zhang, Yi Bian, Tay-Rong Chang, Horng-Tay Jeng, Arun Bansil, Han Hsu, Shuang Jia, Titus Neupert, Hsin Lin, Jia-Xin Yin, Songtian S. Zhang, Hang Li, Kun Jiang, Bingjing Zhang, Cheng Xiang, Hao Zheng, Tyler A. Cochran, Daniel Multer, Guang Bian, Kai Liu, Zhong-Yi Lu, Ziqiang Wang, Shuang Jia, Wenhong Wang, Biao Lian, Benjamin J. Wieder, Frank Schindler, Di Wu, Titus Neupert and Tay-Rong Changâ *DOE/BES (DE-FG-02-05ER46200) and GBMF4547 (EPIQS initiative)
Non-QuantumHall-like Topo Matter
Non-QuantumHall-like Topological Matter configuration options
Hasan, M. Z., Xu, S.-Y. & Bian, G.
Topological insulators, topological superconductors and Weyl fermion semimetals: discoveries, perspectives and outlooks.
Phys. Scr. 2015, 014001 (2015).
â.. recent experimental discoveries of non-quantum-Hall-like topological insulators, topological superconductors, Weyl semimetals and other topological states of matter also signal a clear departure from the quantum-Hall-effect-like transport paradigm that has dominated the field since the 1980s. It is these new forms of matter that enabled realizations of topological-Dirac, Weyl cones, helical-Cooper-pairs, Fermi-arc-quasiparticles and other emergent phenomena in fine-tuned photoemission (ARPES) experiments since ARPES experiments directly allow the study of bulk-boundary (topological) correspondence. In this proceeding we provide a brief overview of the key experiments and discuss our perspectives regarding the new research frontiers enabled by these experiments. Taken collectively, we argue in favor of the emergence of 'topological-condensed-matter-physics' in laboratory experiments...â (Non-QuantumHall-like Topological Matter)
Quantum-Hall-like Topological Matter are described by Chern (or âfractional Chern numbersâ) with or without magnetic fields.
Our primary focus is on new states of matter (Non-Quantum Hall-like topological matter).
Opening Plenary Lecture at Quantum 2025, France
New Frontiers in Topological Quantum Matter (Q. many-body physics)
New Phases of Matter (beyond quantum Hall)
New Phases of Matter (beyond quantum Hall):
According to U.S. Department of Energy, these âexperiments led to seminal discoveries of new phases of matter and new fermionic quasiparticles.â The research work on topological quantum matter âopened new areas in condensed matter physics and holds promise for future transformative applications in materials sciencesâ
Non-QuantumHall-like Topological Matter
Hasan, M. Z., Xu, S.-Y. & Bian, G.
Phys. Scr. 2015, 014001 (2015).
â.. recent experimental discoveries of non-quantum-Hall-like topological insulators, topological superconductors, Weyl semimetals and other topological states of matter also signal a clear departure from the quantum-Hall-effect-like transport paradigm that has dominated the field since the 1980s. It is these new forms of matter that enabled realizations of topological-Dirac, Weyl cones, helical-Cooper-pairs, Fermi-arc-quasiparticles and other emergent phenomena in fine-tuned photoemission (ARPES) experiments since ARPES experiments directly allow the study of bulk-boundary (topological) correspondence. In this proceeding we provide a brief overview of the key experiments and discuss our perspectives regarding the new research frontiers enabled by these experiments. Taken collectively, we argue in favor of the emergence of 'topological-condensed-matter-physics' in laboratory experiments...â (Non-QuantumHall-like Topological Matter)
Textbook inclusion
Textbook inclusion of Experimental Results from our Lab : A few of our results, including Topological Insulators and Weyl-Dirac Semimetals, are now included in many standard textbooks of condensed matter physics [see, for example, âModern Condensed Matter Physicsâ by K. Yang and Steven Girvin (Yale University) ]
New Physics: Beyond all forms of quantum Hall paradigm..
New Physics: Beyond all forms of quantum Hall paradigm..
Unexpected and unpredicted novel (many-body, correlated) quantum phenomena in Topological Kagome Magnets & Superconductors:
Unexpected and unpredicted novel (many-body, correlated) quantum phenomena in Topological Kagome Magnets & Superconductors:
Experiments started in 2017, completed in 2017, Natureâ18, NaturePhysâ19, PRLâ19, PRLâ20, NatureComâ20a, NatureComâ20b, NatureComâ20c, Natureâ20, NatureMatâ21, PRLâ21, Scienceâ19, Natureâ19, Natureâ22a, Natureâ22b, PRLâ22, NaturePhysâ22, NatureComâ22, NatureComâ23a, NatureComâ23b, NaturePhysâ23, NatureComâ24a, NatureComâ24b, NatureComâ24c, NatureMatâ24
Novel quantum phenomena in Topological kagome magnets and superconductors (Nature 2022) :
Inventions, Breakthroughs & Patents ..
Hasan Lab Inventions, Breakthroughs & Patents ..
Opening Keynote (Plenary Session) Lecture at Quantum 2025, France
Opening Keynote (Plenary Session) Lecture at Quantum Science & Engineering 2025, France
AI in physics: A machine learning based classifier for topological quantum materials
A machine learning based classifier for topological quantum matter
Chirality & Topology: Princeton scientists discover topological chiral crystals exhibiting exotic quantum effects
Chirality & Topology: Princeton scientists discover topological chiral crystals exhibiting exotic quantum effects
Theoretical Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class (Bi2Se3 class) with spin-polarized single-Dirac-cone on the surface
Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class (Bi2Se3 class) with spin-polarized single-Dirac-cone on the surface
Theoretical Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class (Bi2Se3 class) with spin-polarized single-Dirac-cone on the surface
Topological CMP ..
https://online.kitp.ucsb.edu/online/lsmatter_c15/hasan/oh/59.html
Topological Condensed Matter Physics -â Topological Quantum Science & Engineering
Unexpected discoveries ...
Unexpected and unpredicted novel (many-body, correlated) quantum phenomena in Topological Kagome Magnets & Superconductors:
Unexpected and unpredicted novel (many-body, correlated) quantum phenomena in Topological Kagome Magnets & Superconductors:
Experiments started in 2017, completed in 2017, Natureâ18, NaturePhysâ19, PRLâ19, PRLâ20, NatureComâ20a, NatureComâ20b, NatureComâ20c, Natureâ20, NatureMatâ21, PRLâ21, Scienceâ19, Natureâ19, Natureâ22a, Natureâ22b, PRLâ22, NaturePhysâ22, NatureComâ22, NatureComâ23a, NatureComâ23b, NaturePhysâ23, NatureComâ24a, NatureComâ24b, NatureComâ24c, NatureMatâ24
Novel quantum phenomena in Topological kagome magnets and superconductors (Nature 2022) :
Quantum Metaphysics:
âExperiment is the only means of knowledge at our disposal. Everything else is poetry, imagination (not guaranteed by nature)â â Max Planck.
High Precision Advanced Experimental Techniques & Novel Instrumentation
High Precision Advanced Experimental Techniques & Novel Instrumentation https://zahidhasangroup.scholar.princeton.edu/research-highlights
Partial Funding : Moore foundation https://www.moore.org/investigator-detail?investigatorId=hasan
Quantum Insight into Matter Itself ..
https://www.pnas.org/doi/10.1073/pnas.1611504113
News: Proceedings of the National Academy of Sciences
Partial Funding : U.S. DOE
PMI/Princeton: https://materials.princeton.edu/people/m-zahid-hasan
Overall impact on research: https://www.amacad.org/person/m-zahid-hasan
(Unexpected and unpredicted) Discovery of novel quantum phenomena in Topological kagome magnets and superconductors
Unexpected and unpredicted novel (many-body, correlated) quantum phenomena in Topological Kagome Magnets & Superconductors:
Experiments started in 2017, completed in 2017, Natureâ18, NaturePhysâ19, PRLâ19, PRLâ20, NatureComâ20a, NatureComâ20b, NatureComâ20c, Natureâ20, NatureMatâ21, PRLâ21, Scienceâ19, Natureâ19, Natureâ22a, Natureâ22b, PRLâ22, NaturePhysâ22, NatureComâ22, NatureComâ23a, NatureComâ23b, NaturePhysâ23, NatureComâ24a, NatureComâ24b, NatureComâ24c, NatureMatâ24, NaturePhysics'25 : Discovery of novel quantum phenomena in Topological kagome magnets and superconductors : https://www.nature.com/articles/s41586-022-05516-0
Quantum many-body physics in doped Mott insulators, Charge-order and Superconductivity competition, Nematic order & fluctuations etc.
Hasan et.al., Phys. Rev. Lett. 92, 246402 (2004); Phys. Rev. Lett. 96, 046407 (2006); Phys. Rev. Lett. 97, 186405 (2006); Phys. Rev. Lett. 96, 216405 (2006). Phys. Rev. Lett. 98, 117007 (2007) and Phys. Rev. Lett. 99, 167002 (2007). Phys. Rev. B 78, 184508 (2008); Phys. Rev. Lett. 103, 037002 (2009). Natureâ18, NaturePhysâ19, PRLâ19, PRLâ20, NatureComâ20a, NatureComâ20b, NatureComâ20c, Natureâ20, NatureMatâ21, PRLâ21, Scienceâ19, Natureâ19, Natureâ22a, Natureâ22b, PRLâ22, NaturePhysâ22, NatureComâ22, NatureComâ23a, NatureComâ23b, NaturePhysâ23, NatureComâ24a, NatureComâ24b, NatureComâ24c, NatureMatâ24, NaturePhysics'25
Princeton scientists discover a âtuneableâ novel correlated quantum state of matter
Hasan and his colleagues, whose research appears in the current issue of Nature, are calling their discovery a ânovelâ quantum state of matter because it is not explained by existing theories of material properties.
Discovery of charge density wave in a kagome lattice strongly correlated antiferromagnet
Discovery of charge density wave in a kagome lattice antiferromagnet
Unconventional Photocurrents from Surface Fermi Arcs in Topological Chiral Crystals (Chirality & Topology)
Unconventional Photocurrents from Surface Fermi Arcs in Topological Chiral Crystals (Chirality & Topology)
Momentum-resolved resonant inelastic X-ray scattering as a novel tool to study electronic structure of correlated insulators
Momentum-resolved resonant inelastic X-ray scattering as a novel tool to study complex Mott insulators
Discovery of Charge Order and Corresponding Edge State in Strongly Correlated Kagome Magnet
Discovery of Charge Order and Corresponding Edge State in Strongly Correlated Kagome Magnet
Princeton-led team discovers unexpected quantum behavior (chiral q. many-body effect) in kagome lattice
Princeton-led team discovers unexpected quantum behavior (chiral q. many-body effect) in kagome lattice
Discovery of a Stripe (charge-ordered) Phase in an Elemental Solid
Discovery of a Stripe (charge-ordered) Phase in an Elemental Solid
Princeton Scientists Discover Exotic Quantum Interference Effect in a Topological Insulator Device
Princeton Scientists Discover Exotic Quantum Interference Effect in a Topological Insulator Device
Theory: âTopological chiral crystalsâ
Theory: âTopological chiral crystalsâ: Topological quantum properties of chiral crystals
Recent STM/STS publications in news:
"Discovery of a Quantum Limit Chern Magnet" and related STM/STS (Hasan Lab work) papers:
Nature 562, 091-095 (2018).
Nature 583, 533-536 (2020).
NATURE 602, 245-250 (2022)
NATURE 609, 490-495 (2022)
Nature 612, 647â657 (2022)
Nature 628, 527-533 (2024)
Momentum-Resolved Collective Charge Excitations (holons) in a Prototype 1D Mott Insulator
Dispersion relation of holons (Momentum-Resolved Collective Charge Excitations in a Prototype 1D Mott Insulator in the presence of spin-charge separation
Correlated electronic structure of Mott insulators probed by inelastic X-ray scattering (Hasan et.al., Science 2000)
https://collaborate.princeton.edu/en/publications/electronic-structure-âŠ
Hasan et.al., Inelastic X-ray Scattering as a Novel Tool to Study Electronic Excitations in Correlated Insulators
https://inspirehep.net/literature/570496
Scientists discover an unusual chiral quantum state (many-body physics) in a topological material
âTo tackle this, graduate student Zi-Jia Cheng and postdoctoral researcher Shafayat Hossain, two co-lead authors of the paper, engineered a scanning photocurrent microscope capable of detecting this topological materialâs nonlinear electromagnetic response under circularly polarized light. This microscope is different from a scanning tunneling microscope, which has typically been used in these types of experiments. The SPCM, though not as high resolution as the STM, is used when the goal is to characterize optically active materials and study their photocurrent behavior at a local scale. A combination of STM and SPCM then provides the complete imaging of the many-body quantum wavefunction.â
Experimental signatures of phase interference and sub-femtosecond time dynamics on the incident energy axis of resonant inelastic x-ray scattering
Experimental signatures of phase interference and sub-femtosecond time dynamics on the incident energy axis of resonant inelastic x-ray scattering
Hasan et.al., Inelastic X-ray Scattering as a Novel Tool to Study Electronic Excitations in Correlated Insulators
https://inspirehep.net/literature/570496
Intertwining of Magnetism and Charge Ordering in Kagome Magnets
Intertwining of Magnetism and Charge Ordering in Kagome FeGe
Adiabatic transformation as a search tool for new topological materials:
https://collaborate.princeton.edu/en/publications/adiabatic-transformatâŠ
Quantum Frontiers ...
Topology & Chirality: The Best Topological Conductor Yet: Spiraling Crystal Is the Key to Exotic Discovery
Now, a team of researchers led by Princeton University working at the Department of Energyâs Lawrence Berkeley National Laboratory (Berkeley Lab) has discovered the strongest topological conductor yet, in the form of thin crystal samples that have a spiral-staircase structure. The teamâs study of crystals, dubbed topological chiral crystals, is reported in the March 20 edition of the journal Nature.
Observation of topological order in a superconducting doped topological insulator
Observation of topological order in a superconducting doped topological insulator
Signatures of a Weyl semimetal with only four Weyl points
Signatures of a Weyl semimetal with only four Weyl points
A New Paradigm : A Novel Method (see, invited review, Rev. of Mod. Phys. 82, 3045, 2010) for decisively measuring "topological invariants"
Chern number w/o Hall transport measurements..
Topological Invariants from Spectroscopy ..
Intrinsic fully bulk INSULATING 3D-Topo-Insulators (Nature Physics 2014)
Intrinsic fully bulk INSULATING 3D-Topo-Insulators (Nature Physics 2014)
https://online.kitp.ucsb.edu/online/lsmatter_c15/hasan/oh/17.html
APS-Physics: "Topological Invariants via Spectroscopy (New Methods)
APS-Physics: "Topological Invariants via Spectroscopy (New Methods)
Topo Invariants precisely define a New Topo State of Matter which can be precisely measured via Spectroscopic measurements (no transport or quantum Hall transport is needed). This invited talk at APS-Physics elaborates this NEW method which enabled discovery of many novel topological states of matterâŠ
Fermi-Arcs: Discovery of Fermi-Arc (Dirac-string) states in Topo Metals..
Fermi-Arcs: Discovery of Fermi-Arc (Dirac-string) states in Topo Metals..
Science (2014)
A New Paradigm : A Novel Method (Rev. of Mod. Phys. 82, 3045, 2010) for decisively measuring "Topological Invariants"
A New Paradigm : A Novel Method (Rev. of Mod. Phys. 82, 3045, 2010) for decisively measuring "Topological Invariants"
A New Paradigm : A Novel Method (see, invited review, RMP 82, 3045, 2010) for decisively measuring "topological invariants" which led to the creation of a new continent of research (the field of topological materials) with multiple groundbreaking discoveries, including topo. Dirac-Weyl fermions, Fermi arc and more..
https://journals.aps.org/rmp/abstract/10.1103/RevModPhys.82.3045
Physics World feature article (Feb 2011)
SPCM
Spectroscopy ..
Spectroscopy ..
Topological Matter ..
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Text Book Inclusion : Girvin & Yang (Cambridge Univ. Press)
New Methods ...
Unexpected and unpredicted novel (many-body, correlated) quantum phenomena in Topological Kagome Magnets & Superconductors:
Unexpected and unpredicted novel (many-body, correlated) quantum phenomena in Topological Kagome Magnets & Superconductors:
Experiments started in 2017, completed in 2017, Natureâ18, NaturePhysâ19, PRLâ19, PRLâ20, NatureComâ20a, NatureComâ20b, NatureComâ20c, Natureâ20, NatureMatâ21, PRLâ21, Scienceâ19, Natureâ19, Natureâ22a, Natureâ22b, PRLâ22, NaturePhysâ22, NatureComâ22, NatureComâ23a, NatureComâ23b, NaturePhysâ23, NatureComâ24a, NatureComâ24b, NatureComâ24c, NatureMatâ24
Novel quantum phenomena in Topological kagome magnets and superconductors (Nature 2022) :
Weyl ...
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Early works on 3D-TI ..
--
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Hasan team demonstrated novel methods to measure topo invariants beyond Chern numbers
Hasan team demonstrated novel methods to measure topo invariants beyond Chern numbers without measuring transport of Hall transport (Science 2009, RMP 2010). It is this new method of measuring topological invariants (RMP 2010) that led to a new experimental revolution in the field, which additionally uncovered many unpredicted and unexpected novel quantum phenomena not envisioned by theory (Nature 2022).
A vast majority of our experimental works are based on our groupâs own theoretical predictions
A vast majority of our experimental works are based on our groupâs own theoretical predictions of topological materials (see, for example) :
Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class (Bi2Se3 class) with spin-polarized single-Dirac-cone on the surface
https://arxiv.org/abs/0908.3513 (2009)
(Theoretical Prediction of Weyl semimetals in 2012)
"Topological Electronic Structure and WEYL Semimetal in the TlBiSe Class,"
Physical Review B 86, 115208 (2012).
"New Type of Weyl Semimetal with Quadratic Double Weyl Fermions,"
Proc. Natl. Acad. Sci. 113, 1180 (2015).
"A Weyl Fermion Semimetal with Surface Fermi Arcs in the Transition Metal Mono-pnictide TaAs Class,"
Nature Commun. 6:7373 (2015).
"Room-temperature Magnetic Weyl Semimetal and Nodal Line Semimetal States in Co2TiX (X=Si, Ge, or Sn),"
https://www.arxiv.org/pdf/1604.02124v1 (2016)
"Theoretical Prediction of Magnetic Weyl Semimetal States in the R-Al-X Family of Compounds" Physical Review B 97, 041104 (2018)
(Theoretical Prediction of ) Topological Hopf and Chain Link Semimetal States and Their Applications
Physical Review Letters 119, 156401 (2017)
(Theoretical Prediction of ) "Topological Quantum Properties of Weyl Chiral Crystals,"
Nature Materials 17, 978-985 (2018).
Discovery of 2D & 3D Topological Magnets :
Discovery of 2D & 3D Topological Magnets :
Theory and Experiments : âIn this talk I present our* theoretical and experimental works on 2D and 3D topological magnets in novel Weyl and Dirac materials building up on earlier result but including recent results "A three-dimensional magnetic topological phase" Ilya Belopolski et.al., arXiv:1712.09992 (2017); "Topological quantum properties of chiral crystals" Guoqing Chang et.al., Nature Materials (2018); "Topological Hopf and Chain Link Semimetal States and Their Application to Co2MnGa" Physical Review Letters 119, 156401 (2017); "Magnetic Weyl fermion semimetals in the R-AlGe family of compounds" Physical Review B (2018) and Jiaxin Yin, Songtian Zhang et.al., "Giant and anisotropic many-body spinâorbit tunability in a strongly correlated kagome magnet" NATURE 562, 91â95 (2018). *Guoqing Chang, Bahadur Singh, Su-Yang Xu, Guang Bian, Shin-Ming Huang, Chuang-Han Hsu, Ilya Belopolski, Nasser Alidoust, Daniel S Sanchez, Hao Zheng, Hong Lu, Xiao Zhang, Yi Bian, Tay-Rong Chang, Horng-Tay Jeng, Arun Bansil, Han Hsu, Shuang Jia, Titus Neupert, Hsin Lin, Jia-Xin Yin, Songtian S. Zhang, Hang Li, Kun Jiang, Bingjing Zhang, Cheng Xiang, Hao Zheng, Tyler A. Cochran, Daniel Multer, Guang Bian, Kai Liu, Zhong-Yi Lu, Ziqiang Wang, Shuang Jia, Wenhong Wang, Biao Lian, Benjamin J. Wieder, Frank Schindler, Di Wu, Titus Neupert and Tay-Rong Changâ *DOE/BES (DE-FG-02-05ER46200) and GBMF4547 (EPIQS initiative)
Discovery of a topological exciton insulator with tunable momentum order
Discovery of a topological exciton insulator with tunable momentum order
Princeton scientists discover a âtuneableâ novel quantum state of matter
Princeton scientists discover a âtuneableâ novel quantum state of matter
Scientists discover an unusual chiral quantum state in a topological material
Scientists discover an unusual chiral quantum state in a topological material
Princeton Scientists Discover Exotic Quantum State at Room Temperature
Princeton Scientists Discover Exotic Quantum State at Room Temperature https://thequantuminsider.com/2022/10/29/princeton-scientists-discover-exotic-quantum-state-at-room-temperature/
Exotic (strongly correlated) superconductivity and the fate of P.W. Anderson theorem
Exotic (strongly correlated) superconductivity and the fate of P.W. Anderson theorem
Topology & Chirality: Topological chiral crystals with helicoid-arc quantum states
Topology & Chirality: Topological chiral crystals with helicoid-arc quantum states
Chiral Crystals and k-space Magnetic Monopoles
Chiral Weyl Crystals and Magnetic Monopoles
Unique duality: Princeton-led team discovers âexoticâ superconductor with metallic surface
Unique duality: Princeton-led team discovers âexoticâ superconductor with metallic surface
Charge order and superconductivity in kagome materials
Charge order and superconductivity in kagome materials
Weyl fermion discovery named Top Ten Breakthrough..[Patent # US10214797B2]
Quantum topological frontiers ..
Weyl Fermions Found, a Quasiparticle That Acts Like a Massless Electron
Weyl Fermions Found, a Quasiparticle That Acts Like a Massless Electron
A New Paradigm : A Novel Method (see, invited review, Rev. of Mod. Phys. 82, 3045, 2010) for decisively measuring "topological invariants" A New Paradigm : A Novel Method (see, invited review, Rev. of Mod. Phys. 82, 3045, 2010) for decisively measuring "
Spin-resolved ARPES as a probe of topological quantum spin Hall effect and Berry's phase
First direct observation of Spin-textures in Topological Insulators : Spin-resolved ARPES as a probe of topological quantum spin Hall effect and Berry's phase
APS-Physics: "Topological Invariants via Spectroscopy (New Methods)
APS-Physics: "Topological Invariants via Spectroscopy (New Methods)
Topo Invariants precisely define a New Topo State of Matter which can be precisely measured via Spectroscopic measurements (no transport or quantum Hall transport is needed). This invited talk at APS-Physics elaborates this NEW method which enabled discovery of many novel topological states of matterâŠ
Fermi-Arcs: Discovery of Fermi-Arc (Dirac-string) states in Topo Metals..
Fermi-Arcs: Discovery of Fermi-Arc (Dirac-string) states in Topo Metals..
Science (2014)
Theoretical Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class (Bi2Se3 class) with spin-polarized single-Dirac-cone on the surface
Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class (Bi2Se3 class) with spin-polarized single-Dirac-cone on the surface
Theoretical Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class (Bi2Se3 class) with spin-polarized single-Dirac-cone on the surface
KITP Lecture .. https://www.on.kitp.ucsb.edu/online/lowdim09/hasan/oh/59.html
KITP Lecture on Quantum Topology
https://www.on.kitp.ucsb.edu/online/lowdim09/hasan/oh/59.html
SPCM
New Methods ...
Hasan team demonstrated novel methods to measure topo invariants beyond Chern numbers
Hasan team demonstrated novel methods to measure topo invariants beyond Chern numbers without measuring transport of Hall transport (Science 2009, RMP 2010). It is this new method of measuring topological invariants (RMP 2010) that led to a new experimental revolution in the field, which also uncovered many unexpected novel quantum phenomena not envisioned by theory (Nature 2022). The methodologies introduced by him to explore and discover topo materials and phenomena are being used by others worldwide to further advance the field and have led to new discoveries
Non-QuantumHall-like Topo Matter
Non-QuantumHall-like Topological Matter configuration options
Hasan, M. Z., Xu, S.-Y. & Bian, G.
Topological insulators, topological superconductors and Weyl fermion semimetals: discoveries, perspectives and outlooks.
Phys. Scr. 2015, 014001 (2015).
â.. recent experimental discoveries of non-quantum-Hall-like topological insulators, topological superconductors, Weyl semimetals and other topological states of matter also signal a clear departure from the quantum-Hall-effect-like transport paradigm that has dominated the field since the 1980s. It is these new forms of matter that enabled realizations of topological-Dirac, Weyl cones, helical-Cooper-pairs, Fermi-arc-quasiparticles and other emergent phenomena in fine-tuned photoemission (ARPES) experiments since ARPES experiments directly allow the study of bulk-boundary (topological) correspondence. In this proceeding we provide a brief overview of the key experiments and discuss our perspectives regarding the new research frontiers enabled by these experiments. Taken collectively, we argue in favor of the emergence of 'topological-condensed-matter-physics' in laboratory experiments...â (Non-QuantumHall-like Topological Matter)
Quantum-Hall-like Topological Matter are described by Chern (or âfractional Chern numbersâ) with or without magnetic fields.
Our primary focus is on new states of matter (Non-Quantum Hall-like topological matter).
Discovery of New Phases of Quantum Matter
First examples of non-quantum-Hall-like topological states of matter (3DTIs, Weyl Semimetals, 3D topological magnets etc.)
https://www.energy.gov/science/articles/energy-secretary-brouillette-anâŠ
Discovery of Topological Surface states (2004-2007)
2007 public conference proceeding at KITP report : https://www.on.kitp.ucsb.edu/online/motterials07/hasan/
Theoretical Prediction and experimental discovery of novel topological materials and quantum phenomena
Funding for âTheoretical Prediction and discovery of novel topological materials and phenomenaâ
https://www.moore.org/investigator-detail?investigatorId=hasan 
Discovery of a topological exciton insulator with tunable momentum order
Discovery of a topological exciton insulator with tunable momentum order
Observation of topological surface state quantum Hall effect in an intrinsic three-dimensional topological insulator
Observation of topological surface state quantum Hall effect in an intrinsic three-dimensional topological insulator
Coining the term "Topological Quantum Matter" (2007)
Nature Physics (Top-10) 2005-2015
APS-Physics: "Topological Invariants via Spectroscopy (New Methods)
APS-Physics: "Topological Invariants via Spectroscopy (New Methods)
Topo Invariants precisely define a New Topo State of Matter which can be precisely measured via Spectroscopic measurements (no transport or quantum Hall transport is needed). This invited talk at APS-Physics elaborates this NEW method which enabled discovery of many novel topological states of matterâŠ
Fermi-Arcs: Discovery of Fermi-Arc (Dirac-string) states in Topo Metals..
Fermi-Arcs: Discovery of Fermi-Arc (Dirac-string) states in Topo Metals..
Science (2014)
A New Paradigm : A Novel Method (Rev. of Mod. Phys. 82, 3045, 2010) for decisively measuring "Topological Invariants"
A New Paradigm : A Novel Method (Rev. of Mod. Phys. 82, 3045, 2010) for decisively measuring "Topological Invariants"
A New Paradigm : A Novel Method (see, invited review, RMP 82, 3045, 2010) for decisively measuring "topological invariants" which led to the creation of a new continent of research (the field of topological materials) with multiple groundbreaking discoveries, including topo. Dirac-Weyl fermions, Fermi arc and more..
https://journals.aps.org/rmp/abstract/10.1103/RevModPhys.82.3045
Theoretical Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class (Bi2Se3 class) with spin-polarized single-Dirac-cone on the surface
Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class (Bi2Se3 class) with spin-polarized single-Dirac-cone on the surface
Theoretical Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class (Bi2Se3 class) with spin-polarized single-Dirac-cone on the surface
KITP Lecture..
Field-creation: Topo Q. Matter
Unexpected and unpredicted novel (many-body, correlated) quantum phenomena in Topological Kagome Magnets & Superconductors:
Unexpected and unpredicted novel (many-body, correlated) quantum phenomena in Topological Kagome Magnets & Superconductors:
Experiments started in 2017, completed in 2017, Natureâ18, NaturePhysâ19, PRLâ19, PRLâ20, NatureComâ20a, NatureComâ20b, NatureComâ20c, Natureâ20, NatureMatâ21, PRLâ21, Scienceâ19, Natureâ19, Natureâ22a, Natureâ22b, PRLâ22, NaturePhysâ22, NatureComâ22, NatureComâ23a, NatureComâ23b, NaturePhysâ23, NatureComâ24a, NatureComâ24b, NatureComâ24c, NatureMatâ24
Novel quantum phenomena in Topological kagome magnets and superconductors (Nature 2022) :
--
Hasan team demonstrated novel methods to measure topo invariants beyond Chern numbers
Hasan team demonstrated novel methods to measure topo invariants beyond Chern numbers without measuring transport of Hall transport (Science 2009, RMP 2010). It is this new method of measuring topological invariants (RMP 2010) that led to a new experimental revolution in the field, which also uncovered many unexpected novel quantum phenomena not envisioned by theory (Nature 2022). The methodologies introduced by him to explore and discover topo materials and phenomena are being used by others worldwide to further advance the field and have led to new discoveries
A vast majority of our experimental works are based on our groupâs own theoretical predictions
A vast majority of our experimental works are based on our groupâs own theoretical predictions of topological materials (see, for example) :
Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class (Bi2Se3 class) with spin-polarized single-Dirac-cone on the surface
https://arxiv.org/abs/0908.3513 (2009)
(Theoretical Prediction of Weyl semimetals in 2012)
"Topological Electronic Structure and WEYL Semimetal in the TlBiSe Class,"
Physical Review B 86, 115208 (2012).
"New Type of Weyl Semimetal with Quadratic Double Weyl Fermions,"
Proc. Natl. Acad. Sci. 113, 1180 (2015).
"A Weyl Fermion Semimetal with Surface Fermi Arcs in the Transition Metal Mono-pnictide TaAs Class,"
Nature Commun. 6:7373 (2015).
"Room-temperature Magnetic Weyl Semimetal and Nodal Line Semimetal States in Co2TiX (X=Si, Ge, or Sn),"
https://www.arxiv.org/pdf/1604.02124v1 (2016)
"Theoretical Prediction of Magnetic Weyl Semimetal States in the R-Al-X Family of Compounds" Physical Review B 97, 041104 (2018)
(Theoretical Prediction of ) Topological Hopf and Chain Link Semimetal States and Their Applications
Physical Review Letters 119, 156401 (2017)
(Theoretical Prediction of ) "Topological Quantum Properties of Weyl Chiral Crystals,"
Nature Materials 17, 978-985 (2018).
Opening Keynote (Plenary Session) Lecture at Quantum2025, France
| The 5th edition of the Quantum Matter International Conference â QUANTUMatter 2025 (Grenoble, France) â aims at gathering the various communities engaged in the science and technologies of quantum information and quantum matter, to foster the incubation of new ideas & collaborations at the forefront of quantum technologies, emerging quantum materials and novel generations of quantum communication protocols, quantum sensing and quantum simulation. |
IQIM- CalTech : Lecture on "New Frontiers on Topological Quantum Physics"
Tuning a topological insulator featuring a Dirac fermion can be used as a platform to realize emergent Weyl fermion and âfractionalâ Fermi surfaces; and can also lead to correlated magnetic, Chern, or many-body states. The kagome lattice, which features Dirac fermions, flat bands, and van Hove singularities, can serve as the platform to explore topology, strong correlation, exotic superconductivity, emergent chirality, and many-body density-wave phenomena, as shown in a series of recent works, including some new developments. These topological quantum matters harbor novel properties that provide versatile platforms for the development of next-generation quantum devices.
The ETH-Zurich physics colloquium
The ETH-Zurich physics colloquium
https://colloquium.phys.ethz.ch/programme/previous/autumn23/Hasan.html
Intrinsic fully bulk INSULATING 3D-Topo-Insulators (Nature Physics 2014)
Intrinsic fully bulk INSULATING 3D-Topo-Insulators (Nature Physics 2014)
https://online.kitp.ucsb.edu/online/lsmatter_c15/hasan/oh/17.html
Unexpected and unpredicted novel (many-body, correlated) quantum phenomena in Topological Kagome Magnets & Superconductors:
Unexpected and unpredicted novel (many-body, correlated) quantum phenomena in Topological Kagome Magnets & Superconductors:
Experiments started in 2017, completed in 2017, Natureâ18, NaturePhysâ19, PRLâ19, PRLâ20, NatureComâ20a, NatureComâ20b, NatureComâ20c, Natureâ20, NatureMatâ21, PRLâ21, Scienceâ19, Natureâ19, Natureâ22a, Natureâ22b, PRLâ22, NaturePhysâ22, NatureComâ22, NatureComâ23a, NatureComâ23b, NaturePhysâ23, NatureComâ24a, NatureComâ24b, NatureComâ24c, NatureMatâ24
Novel quantum phenomena in Topological kagome magnets and superconductors : https://www.nature.com/articles/s41586-022-05516-0
Fermi-Arcs: Discovery of Fermi-Arc (Dirac-string) states in Topo Metals..
Fermi-Arcs: Discovery of Fermi-Arc (Dirac-string) states in Topo Metals..
Science (2014)
Why Weyl ...
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Bose-Einstein centenary lectures (2024), The birth of quantum physics ..
Prof. Hasan was invited to deliver the Bose-Einstein centenary lectures in quantum physics in celebrating the 100th anniversary of collaboration between S.N. Bose (Bosons) and Albert Einstein on the birth of quantum physics :
https://www.linkedin.com/feed/update/urn:li:activity:727666104498538086âŠ
Sir Nevill Mott (Nobel Laureate 1977) Lecture Series in Physics
https://www.lboro.ac.uk/departments/physics/events/sir-nevill-mott-lectures/
Previously, delivered by Mott, Anderson, Berry, Rashba, Abrikosov, Penrose, Josephson, Houghton, Pendry, Mansfield, Simons, Kosterlitz and others since 1995 :
https://www.lboro.ac.uk/departments/physics/events/sir-nevill-mott-lectures/
Quantum many-body physics at Hasan Lab
Strongly correlated electron physics at Hasan lab:
Quantum many-body physics in doped Mott insulators, Charge-order and Superconductivity competition, Nematic order & fluctuations etc.
Hasan et.al., Phys. Rev. Lett. 92, 246402 (2004); Phys. Rev. Lett. 96, 046407 (2006); Phys. Rev. Lett. 97, 186405 (2006); Phys. Rev. Lett. 96, 216405 (2006). Phys. Rev. Lett. 98, 117007 (2007) and Phys. Rev. Lett. 99, 167002 (2007). Phys. Rev. B 78, 184508 (2008); Phys. Rev. Lett. 103, 037002 (2009). Natureâ18, NaturePhysâ19, PRLâ19, PRLâ20, NatureComâ20a, NatureComâ20b, NatureComâ20c, Natureâ20, NatureMatâ21, PRLâ21, Scienceâ19, Natureâ19, Natureâ22a, Natureâ22b, PRLâ22, NaturePhysâ22, NatureComâ22, NatureComâ23a, NatureComâ23b, NaturePhysâ23, NatureComâ24a, NatureComâ24b, NatureComâ24c, NatureMatâ24, NaturePhysics'25
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Intrinsic fully bulk INSULATING 3D-Topo-Insulators (Nature Physics 2014)
Intrinsic fully bulk INSULATING 3D-Topo-Insulators (Nature Physics 2014)
https://online.kitp.ucsb.edu/online/lsmatter_c15/hasan/oh/17.html
APS-Physics: "Topological Invariants via Spectroscopy (New Methods)
APS-Physics: "Topological Invariants via Spectroscopy (New Methods)
Topo Invariants precisely define a New Topo State of Matter which can be precisely measured via Spectroscopic measurements (no transport or quantum Hall transport is needed). This invited talk at APS-Physics elaborates this NEW method which enabled discovery of many novel topological states of matterâŠ
KITP Lecture link .. https://www.on.kitp.ucsb.edu/online/lowdim09/hasan/oh/01.html
KITP Lecture link ..
https://www.on.kitp.ucsb.edu/online/lowdim09/hasan/oh/01.html
Fermi-Arcs: Discovery of Fermi-Arc (Dirac-string) states in Topo Metals..
Fermi-Arcs: Discovery of Fermi-Arc (Dirac-string) states in Topo Metals..
Science (2014)
Group Alum:
Previous PhD graduate students from Hasan group at Princeton have gone on to win Pappalardo fellowship (MIT), Urbanic fellowship (Stanford), Simons fellowship (Columbia), Miller Fellowship (UC Berkeley), GLAM fellowship (Stanford), Postdoc at Princeton, Stanford, MIT, Princeton Engineering, Columbia and many other top fellowships or postdoctoral positions at national labs (Berkeley Lab, Argonne, PSI-Zurich, SLAC/Stanford etc.) and industrial internships including at Google (QuantumAI group), IBM, QuEra, Rigetti quantum computing.
Group Alum in Academia ..
A number of Hasan group PhD students have also gone on to win faculty positions at top research institutions such as Caltech, Harvard University, NYU, University of California, Univ of Florida, UCLA, Univ of Minnesota and many others around the world including the national labs such as Berkeley Lab, SLAC/Stanford, PSI-Switzerland etc.
APS-Physics: "Topological Invariants via Spectroscopy (New Methods)
APS-Physics: "Topological Invariants via Spectroscopy (New Methods)
Topo Invariants precisely define a New Topo State of Matter which can be precisely measured via Spectroscopic measurements (no transport or quantum Hall transport is needed). This invited talk at APS-Physics elaborates this NEW method which enabled discovery of many novel topological states of matterâŠ
Topological Quantum Science & Engineering
Topological Quantum Science and Engineering: Hasan lab helped launch the field of Topological Insulators by directly detecting the novel surface states and thoroughly demonstrating their unusual topological properties using advanced spin-sensitive spectroscopic techniques (50,000+ citations). Subsequently, Hasan group has theoretically and experimentally discovered many novel classes of topological matter and topological phase transitions including Topological Magnets (via the demonstration of Chern gap in 2012) using novel instrumentations and innovative methods and introduced designed discovery methods. The field expanded to include topological semimetals, notably Weyl Semimetals, whose states mimic massless fermions considered in quantum field theory. In 2015 Hasan group observed the emergent Weyl fermions and novel topological Fermi arc surface states in several topological semimetals he and his team theoretically predicted in arsenide and other materials. His Weyl fermion work is based on his and his team's theoretical predictions in several spin-orbit materials. Subsequently, he has theoretically and experimentally discovered many novel classes of magnetic topological semimetals. He has also made groundbreaking contributions (theoretical and experimental) in the subfields of topological phase transitions, topological magnets in 2D and 3D, topological nodal-line and drumhead metals, topological magnetic semimetals, topological chiral crystals, topological Hopf link semimetals, topological superconductors, Helicoid-arc quantum states and Kagome magnets and materials, Chern magnets and charge-ordered Kagome superconductors enabled by innovative applications and development of experimental methods. He identified room temperature topological materials. A vast majority of his experimental discoveries are based on his and his team's theoretical predictions of topological materials. These materials are broadly important for future device applications with higher energy efficiency, as quantum information science platforms, and for exploring new emergent or many-body quantum physics. He has also contributed to the conceptual design and theoretical development of some of these topics and written several comprehensive review articles by invitation. The methodologies introduced by him to explore and discover topological materials and phenomena are being used by others world-wide to further advance the field and led to new discoveries. His experiments and methods have been seminal in giving rise to the field of "Topological Quantum Matter" with more than 102,000 citations (over 250 publications with h-factor 115+), which is now growing vigorously at the nexus of condensed matter physics, materials engineering, nano-science, device physics & quantum engineering, chemistry and relativistic quantum field theory as evidenced in all citation tracks.
Source link:
A New Paradigm : A Novel Method (see, invited review, Rev. of Mod. Phys. 82, 3045, 2010) for decisively measuring "topological invariants" A New Paradigm : A Novel Method (see, invited review, Rev. of Mod. Phys. 82, 3045, 2010) for decisively measuring "
Intrinsic fully bulk INSULATING 3D-Topo-Insulators (Nature Physics 2014)
Intrinsic fully bulk INSULATING 3D-Topo-Insulators (Nature Physics 2014)
https://online.kitp.ucsb.edu/online/lsmatter_c15/hasan/oh/17.html
KITP Lecture link .. https://www.on.kitp.ucsb.edu/online/lowdim09/hasan/oh/01.html
KITP Lecture link ..
https://www.on.kitp.ucsb.edu/online/lowdim09/hasan/oh/01.html
Unexpected and unpredicted novel (many-body, correlated) quantum phenomena in Topological Kagome Magnets & Superconductors:
Unexpected and unpredicted novel (many-body, correlated) quantum phenomena in Topological Kagome Magnets & Superconductors:
Experiments started in 2017, completed in 2017, Natureâ18, NaturePhysâ19, PRLâ19, PRLâ20, NatureComâ20a, NatureComâ20b, NatureComâ20c, Natureâ20, NatureMatâ21, PRLâ21, Scienceâ19, Natureâ19, Natureâ22a, Natureâ22b, PRLâ22, NaturePhysâ22, NatureComâ22, NatureComâ23a, NatureComâ23b, NaturePhysâ23, NatureComâ24a, NatureComâ24b, NatureComâ24c, NatureMatâ24
Novel quantum phenomena in Topological kagome magnets and superconductors : https://www.nature.com/articles/s41586-022-05516-0
A New Paradigm : A Novel Method (Rev. of Mod. Phys. 82, 3045, 2010) for decisively measuring "Topological Invariants"
A New Paradigm : A Novel Method (Rev. of Mod. Phys. 82, 3045, 2010) for decisively measuring "Topological Invariants"
A New Paradigm : A Novel Method (see, invited review, RMP 82, 3045, 2010) for decisively measuring "topological invariants" which led to the creation of a new continent of research (the field of topological materials) with multiple groundbreaking discoveries, including topo. Dirac-Weyl fermions, Fermi arc and more..
https://journals.aps.org/rmp/abstract/10.1103/RevModPhys.82.3045
Field-creation..
Textbook inclusion :
Textbook inclusion of Experimental Results from our Lab : A few of our results, including Topological Insulators and Weyl-Dirac Semimetals, are now included in many standard textbooks of condensed matter physics [see, for example, âModern Condensed Matter Physicsâ by K. Yang and Steven Girvin (Yale University) ]
Our method of using advanced SPECTROSCOPIC techniques as novel methods to directly measure topological invariants in old and New Classes of quantum materials is now taught in text books world-wide.
New Methods ...
Early works on 3D-TI ..
Hasan team demonstrated novel methods to measure topo invariants beyond Chern numbers
Hasan team demonstrated novel methods to measure topo invariants beyond Chern numbers without measuring transport of Hall transport (Science 2009, RMP 2010). It is this new method of measuring topological invariants (RMP 2010) that led to a new experimental revolution in the field, which also uncovered many unexpected novel quantum phenomena not envisioned by theory (Nature 2022). The methodologies introduced by him to explore and discover topo materials and phenomena are being used by others worldwide to further advance the field and have led to new discoveries
Non-QuantumHall-like Topo Matter
Non-QuantumHall-like Topological Matter configuration options
Hasan, M. Z., Xu, S.-Y. & Bian, G.
Topological insulators, topological superconductors and Weyl fermion semimetals: discoveries, perspectives and outlooks.
Phys. Scr. 2015, 014001 (2015).
â.. recent experimental discoveries of non-quantum-Hall-like topological insulators, topological superconductors, Weyl semimetals and other topological states of matter also signal a clear departure from the quantum-Hall-effect-like transport paradigm that has dominated the field since the 1980s. It is these new forms of matter that enabled realizations of topological-Dirac, Weyl cones, helical-Cooper-pairs, Fermi-arc-quasiparticles and other emergent phenomena in fine-tuned photoemission (ARPES) experiments since ARPES experiments directly allow the study of bulk-boundary (topological) correspondence. In this proceeding we provide a brief overview of the key experiments and discuss our perspectives regarding the new research frontiers enabled by these experiments. Taken collectively, we argue in favor of the emergence of 'topological-condensed-matter-physics' in laboratory experiments...â (Non-QuantumHall-like Topological Matter)
Quantum-Hall-like Topological Matter are described by Chern (or âfractional Chern numbersâ) with or without magnetic fields.
Our primary focus is on new states of matter (Non-Quantum Hall-like topological matter).
PU-Physics/GoogleScholar
Topological Quantum Matter in the 21st Century ..
APS-Physics: "Topological Invariants via Spectroscopy (New Methods)
APS-Physics: "Topological Invariants via Spectroscopy (New Methods)
Topo Invariants precisely define a New Topo State of Matter which can be precisely measured via Spectroscopic measurements (no transport or quantum Hall transport is needed). This invited talk at APS-Physics elaborates this NEW method which enabled discovery of many novel topological states of matterâŠ
What is New?
Unlike string theory, topological physics in lower dimensional condensed matter systems is an experimental reality since the bulk-boundary correspondence can be probed experimentally in lower dimensions. Recent experimental discoveries of non-quantum-Hall-like topological insulators, topological superconductors, Weyl semimetals and other topological states of matter also signal a clear departure from the quantum-Hall-effect-like transport paradigm that has dominated the field since the 1980s. It is these new forms of matter that enabled realizations of topological-Dirac, Weyl cones, helical-Cooper-pairs, Fermi-arc-quasiparticles and other emergent phenomena in fine-tuned photoemission experiments since such experiments directly allow the study of bulk-boundary (topological) correspondence. Taken collectively, we argue in favor of the emergence of âtopological-condensed-matter-physicsâ in laboratory experiments for which a variety of theoretical concepts over the last 90 years (Dirac-Weyl topology, negative-Dirac-mass, Dirac-monopole-Berry charge, Aharonov-Bohm phase, CHerring's exceptional points (modern Weyl node), Karplus-Luttinger theory (modern Berry curvature), SSH-chain, Jakiw-Rebbi and many foundational theories before 1970s â Topological theories are not new! ) paved the way for modern experiments on Topological Materials! (Materials are not new either)
What is new? Advanced Spectroscopic experiments that enable precise determination of âTopological Invariantsâ (see, for a review, RMP 82, 3045 (2010)