Publications (135)
Visualizing higher-fold topology in chiral crystals
Tyler A Cochran, Ilya Belopolski, Kaustuv Manna +21
Novel topological phases of matter are fruitful platforms for the discovery of unconventional electromagnetic phenomena. Higher-fold topology is one example, where the low-energy d…
Enormous Berry-Curvature-Driven Anomalous Hall Effect in Topological Insulator (Bi,Sb)2Te3 on Ferrimagnetic Europium Iron Garnet beyond 400 K
Wei-Jhih Zou, Meng-Xin Guo, Jyun-Fong Wong +14
To realize the quantum anomalous Hall effect (QAHE) at elevated temperatures, the approach of magnetic proximity effect (MPE) was adopted to break the time-reversal symmetry in the…
Scaling universal Fermi network toward ground states: A diffusion-Monte-Carlo assessment
Yu-Sheng Li, Saskia Poldmaa, Tzen Ong +4
In this work, we show that Fermi Sets---a provably universal neural network architecture for fermionic wavefunctions---can be systematically scaled up to find interacting ground st…
Discovery of a Weyl Fermion semimetal state in NbAs
Su-Yang Xu, Nasser Alidoust, Ilya Belopolski +21
We report the discovery of Weyl semimetal NbAs featuring topological Fermi arc surface states.
Searching for topological Fermi arcs via quasiparticle interference on a type-II Weyl semimetal MoTe
Davide Iaia, Guoqing Chang, Tay-Rong Chang +5
Weyl semimetals display a novel topological phase of matter where the Weyl nodes emerge in pairs of opposite chirality and can be seen as either a source or a sink of Berry curvatu…
Observation of the Axion quasiparticle in 2D MnBiTe
Jian-Xiang Qiu, Barun Ghosh, Jan Schütte-Engel +32
In 1978, Wilczek and Weinberg theoretically discovered a new boson-the Axion-which is the coherent oscillation of the field in QCD. Its existence can solve multiple fundamenta…
Unconventional superconducting pairing in a B20 Kramers Weyl semimetal
Sougata Mardanya, Mehdi Kargarian, Rahul Verma +6
Topological superconductors present an ideal platform for exploring nontrivial superconductivity and realizing Majorana boundary modes in materials. However, finding a single-phase…
A Novel Magnetic Material by Design: Observation of Yb3+ with Spin-1/2 and Possible Superconducting Trace in YbxPt5P
Xin Gui, Tay-Rong Chang, Kaya Wei +5
The localized f-electrons enrich the magnetic properties in rare-earth-based intermetallics. Among those, compounds with heavier 4d and 5d transition metals are even more fascinati…
Atomic Scale Visualization of Quantum Interference on a Weyl Semimetal Surface by Scanning Tunneling Microscopy/Spectroscopy
Hao Zheng, Su-Yang Xu, Guang Bian +19
Weyl semimetals may open a new era in condensed matter physics, materials science and nanotech after graphene and topological insulators. We report the first atomic scale view of t…
Altermagnetism, Kagome Flat Band, and Weyl Fermion States in Magnetically Intercalated Transition Metal Dichalcogenides
Avinash Sah, Ting-Yong Lim, Clayton Conner +5
Altermagnetic (AM) compounds have recently emerged as a promising platform for realizing unconventional quantum phases, enabled by their unique spin-split band structure at zero ne…
Surface Versus Bulk Dirac States Tuning in a Three-Dimensional Topological Dirac Semimetal
Madhab Neupane, Su-Yang Xu, Nasser Alidoust +13
Recently, crystalline-symmetry-protected three-dimensional (3D) bulk Dirac semimetal phase has been experimentally identified in a stoichiometric high-mobility compound, Cd3As2. Th…
Nanoscale interplay of strain and doping in a high-temperature superconductor
Ilija Zeljkovic, Jouko Nieminen, Dennis Huang +10
The highest temperature superconductors are electronically inhomogeneous at the nanoscale, suggesting the existence of a local variable which could be harnessed to enhance the supe…
Topological Nodal-Line Fermions in the Non-Centrosymmetric Superconductor Compound PbTaSe2
Guang Bian, Tay-Rong Chang, Raman Sankar +18
We report the identification of a Topological Nodal-Line Semimetal state in PbTaSe2.
Topological quantum properties of chiral crystals
Guoqing Chang, Benjamin J. Wieder, Frank Schindler +10
Chiral crystals are materials whose lattice structure has a well-defined handedness due to the lack of inversion, mirror, or other roto-inversion symmetries. These crystals represe…
Topological charge-entropy scaling in kagome Chern magnet TbMnSn
Xitong Xu, Jia-Xin Yin, Wenlong Ma +8
In ordinary materials, electrons conduct both electricity and heat, where their charge-entropy relations observe the Mott formula and the Wiedemann-Franz law. In topological quantu…
Magnetic dilution effect and topological phase transitions in (MnPb)BiTe
Tiema Qian, Yueh-Ting Yao, Chaowei Hu +5
As the first intrinsic antiferromagnetic (AFM) topological insulator (TI), MnBiTe has provided a material platform to realize various emergent phenomena arising from the in…
Ultraquantum magnetoresistance in Kramers Weyl semimetal candidate -Ag2Se
Cheng-Long Zhang, Frank Schindler, Haiwen Liu +14
The topological semimetal -Ag2Se features a Kramers Weyl node at the origin in momentum space and a quadruplet of spinless Weyl nodes, which are annihilated by spin-orbit coupl…
Band Topology and Dichroic Signature of Bismuth
Guang Bian, Tay-Rong Chang, Xiaoxiong Wang +3
Bismuth has been the key element in the discovery and development of topological insulator materials. Previous theoretical studies indicated that Bi is topologically trivial and it…
Experimental Observation of Two Massless Dirac-Fermion Gases in Graphene-Topological Insulator Heterostructure
Guang Bian, Ting-Fung Chung, Chang Liu +19
Graphene and topological insulators (TI) possess two-dimensional Dirac fermions with distinct physical properties. Integrating these two Dirac materials in a single device creates…
Direct Transition Resonance in Atomically Uniform Topological Sb(111) Thin Films
Guang Bian, Caizhi Xu, Tay-Rong Chang +8
Atomically uniform Sb(111) films are fabricated by the method of molecular beam epitaxy on an optimized Si(111) surface. Two dimensional quantum well states and topological surface…
Topological Weyl phase transition in MoWTe
Ilya Belopolski, Daniel S. Sanchez, Yukiaki Ishida +21
Topological phases of matter exhibit phase transitions between distinct topological classes. These phase transitions are exotic in that they do not fall within the traditional Ginz…
Engineering axion insulator phase in superlattices with inversion symmetry breaking
Rajibul Islam, Sougata Mardanya, Alexander Lau +6
We study theoretically the interplay between magnetism and topology in three-dimensional HgTe/MnTe superlattices stacked along the (001) axis. Our results show the evolution of the…
Prediction of Nontrivial Band Topology and Superconductivity in MgPb
Guang Bian, Tay-Rong Chang, Angus Huang +5
The interplay of BCS superconductivity and nontrivial band topology is expected to give rise to opportunities for creating topological superconductors, achieved through pairing spi…
Layer Hall effect in a 2D topological Axion antiferromagnet
Anyuan Gao, Yu-Fei Liu, Chaowei Hu +33
While ferromagnets have been known and exploited for millennia, antiferromagnets (AFMs) were only discovered in the 1930s. The elusive nature indicates AFMs' unique properties: At…
Room temperature nonlinear Hall effect and wireless RF rectification in Weyl semimetal TaIrTe4
Dushyant Kumar, Chuang-Han Hsu, Raghav Sharma +6
The nonlinear Hall effect (NLHE), which can produce a transverse voltage without any magnetic field, is a potential alternative for rectification or frequency doubling. However, th…
Termination Dependent Topological Surface States in Nodal Loop Semimetal HfP2
Christopher Sims, M. Mofazzel Hosen, Hugo Aramberri +11
Symmetry plays a major role in all disciplines of physics. Within the field of topological materials there is a great interest in understanding how the mechanics of crystalline and…
Measuring Chern numbers above the Fermi level in the Type II Weyl semimetal MoWTe
Ilya Belopolski, Su-Yang Xu, Yukiaki Ishida +30
It has recently been proposed that electronic band structures in crystals give rise to a previously overlooked type of Weyl fermion, which violates Lorentz invariance and, conseque…
Atomic-scale visualization of surface-assisted orbital order
Howon Kim, Yasuo Yoshida, Chi-Cheng Lee +6
Orbital-related physics attracts growing interest in condensed matter research, but direct real-space access of the orbital degree of freedom is challenging. Here we report a first…
Magneto-transport properties of the "hydrogen atom" nodal-line semimetal candidates CaTX (T=Ag, Cd, X=As, Ge)
Eve Emmanouilidou, Bing Shen, Xiaoyu Deng +5
Topological semimetals are characterized by protected crossings between conduction and valence bands. These materials have recently attracted significant interest because of the de…
Direct observation of the transition from indirect to direct bandgap in atomically thin epitaxial MoSe2
Yi Zhang, Tay-Rong Chang, Bo Zhou +13
Quantum systems in confined geometries are host to novel physical phenomena. Examples include quantum Hall systems in semiconductors and Dirac electrons in graphene. Interest in su…
Atomic Scale Quantum Anomalous Hall Effect in Monolayer Graphene/ Heterostructure
Yueh-Ting Yao, Suyang Xu, Tay-Rong Chang
The two-dimensional quantum anomalous Hall (QAH) effect is direct evidence of non-trivial Berry curvature topology in condensed matter physics. Searching for QAH in 2D materials, p…
Quantized Hall current in topological nodal-line semimetal
Po-Hsin Shih, Thi-Nga Do, Godfrey Gumbs +3
Photocurrent acts as one of measurable responses of material to light, which has proved itself to be crucial for sensing and energy harvesting. Topological semimetals with gapless…
Direct Visualization of a Disorder Driven Electronic Smectic Phase in Nonsymmorphic Square-Net Semimetal GdSbTe
Balaji Venkatesan, Syu-You Guan, Jen-Te Chang +14
Electronic liquid crystal (ELC) phases are spontaneous symmetry breaking states believed to arise from strong electron correlation in quantum materials such as cuprates and iron pn…
Discovery of a quantum limit Chern magnet TbMn6Sn6
Jia-Xin Yin, Wenlong Ma, Tyler A. Cochran +23
The quantum level interplay between geometry, topology, and correlation is at the forefront of fundamental physics. Owing to the unusual lattice geometry and breaking of time-rever…
Mirror protected Dirac fermions on a Weyl semimetal NbP surface
Hao Zheng, Guoqing Chang, Shin-Ming Huang +15
The first Weyl semimetal was recently discovered in the NbP class of compounds. Although the topology of these novel materials has been identified, the surface properties are not y…
Hedgehog Spin-texture and Berry's Phase tuning in a Magnetic Topological Insulator
Su-Yang Xu, Madhab Neupane, Chang Liu +18
Understanding and control of spin degrees of freedom on the surfaces of topological materials are key to future applications as well as for realizing novel physics such as the axio…
Unoccupied electronic structure and signatures of topological Fermi arcs in the Weyl semimetal candidate MoWTe
Ilya Belopolski, Su-Yang Xu, Yukiaki Ishida +30
Weyl semimetals have sparked intense research interest, but experimental work has been limited to the TaAs family of compounds. Recently, a number of theoretical works have predict…
Observation of Quantum-Tunneling Modulated Spin Texture in Ultrathin Topological Insulator Bi2Se3 Films
Madhab Neupane, Anthony Richardella, Jaime Sánchez-Barriga +18
Understanding the spin-texture behavior of boundary modes in ultrathin topological insulator films is critically essential for the design and fabrication of functional nano-devices…
Unconventional transformation of spin Dirac phase across a topological quantum phase transition
Su-Yang Xu, Madhab Neupane, Ilya Belopolski +15
The topology of a topological material can be encoded in its surface states. These surface states can only be removed by a bulk topological quantum phase transition into a trivial…
Anomalously high supercurrent density in a two-dimensional topological material
Qi Zhang, Md Shafayat Hossain, Brian Casas +24
Ongoing advances in superconductors continue to revolutionize technology thanks to the increasingly versatile and robust availability of lossless supercurrent. In particular high s…
3D Dirac cone carrier dynamics in Na3Bi and Cd3As2
G. S. Jenkins, C. Lane, B. Barbiellini +12
Optical measurements and band structure calculations are reported on 3D Dirac materials. The electronic properties associated with the Dirac cone are identified in the reflectivity…
Purely rotational symmetry-protected topological crystalline insulator -Bi4Br4
Chuang-Han Hsu, Xiaoting Zhou, Qiong Ma +7
Recent theoretical advances have proposed a new class of topological crystalline insulator (TCI) phases protected by rotational symmetries. Distinct from topological insulators (TI…
CuIr2Te4: A Quasi-Two-Dimensional Ternary Telluride Chalcogenide Superconductor
Dong Yan, Yijie Zeng, Guohua Wang +9
Here we report the first observation of superconductivity in the AB2X4-type ternary telluride CuIr2Te4, which is synthesized by a solid-state method in an evacuated quartz jacket.…
Discovery of topological chiral crystals with helicoid arc states
Daniel S. Sanchez, Ilya Belopolski, Tyler A. Cochran +19
The quantum behaviour of electrons in materials lays the foundation for modern electronic and information technology. Quantum materials with novel electronic and optical properties…
Discovery of topological Weyl fermion lines and drumhead surface states in a room temperature magnet
Ilya Belopolski, Kaustuv Manna, Daniel S. Sanchez +20
Topological matter is known to exhibit unconventional surface states and anomalous transport owing to unusual bulk electronic topology. In this study, we use photoemission spectros…
Experimental discovery of a topological Weyl semimetal state in TaP
Su-Yang Xu, Ilya Belopolski, Daniel S. Sanchez +24
Weyl semimetals are expected to open up new horizons in physics and materials science because they provide the first realization of Weyl fermions and exhibit protected Fermi arc su…
Observation of 2D Weyl Fermion States in Epitaxial Bismuthene
Qiangsheng Lu, P. V. Sreenivasa Reddy, Hoyeon Jeon +20
A two-dimensional (2D) Weyl semimetal featuring a spin-polarized linear band dispersion and a nodal Fermi surface is a new topological phase of matter. It is a solid-state realizat…
Crystal growth and quantum oscillations in the topological chiral semimetal CoSi
Xitong Xu, Xirui Wang, Tyler A. Cochran +10
We survey the electrical transport properties of the single-crystalline, topological chiral semimetal CoSi which was grown via different methods. High-quality CoSi single crystals…
A topological Hund nodal line antiferromagnet
Xian P. Yang, Yueh-Ting Yao, Pengyu Zheng +21
The interplay of topology, magnetism, and correlations gives rise to intriguing phases of matter. In this study, through state-of-the-art angle-resolved photoemission spectroscopy,…
Observation of the spin-polarized surface state in a noncentrosymmetric superconductor BiPd
Madhab Neupane, Nasser Alidoust, M. Mofazzel Hosen +17
Recently, noncentrosymmetric superconductor BiPd has attracted considerable research interest due to the possibility of hosting topological superconductivity. Here we report a syst…
Many-body Resonance in a Correlated Topological Kagome Antiferromagnet
Songtian S. Zhang, Jia-Xin Yin, Muhammad Ikhlas +16
We use scanning tunneling microscopy/spectroscopy (STM/S) to elucidate the atomically resolved electronic structure in strongly correlated topological kagome magnet MnSn. In st…
Unconventional Resistivity Scaling in Topological Semimetal CoSi
Shang-Wei Lien, Ion Garate, Utkarsh Bajpai +9
Nontrivial band topologies in semimetals lead to robust surface states that can contribute dominantly to the total conduction. This may result in reduced resistivity with decreasin…
A New Magnetic Topological Quantum Material Candidate by Design
Xin Gui, Ivo Pletikosic, Huibo Cao +9
Magnetism, when combined with an unconventional electronic band structure, can give rise to forefront electronic properties such as the quantum anomalous Hall effect, axion electro…
Giant and anisotropic many-body spin-orbit tunability in a strongly correlated kagome magnet
Jia-Xin Yin, Songtian S. Zhang, Hang Li +18
Owing to the unusual geometry of kagome lattices-lattices made of corner-sharing triangles-their electrons are useful for studying the physics of frustrated, correlated and topolog…
Atomic-scale visualization of quasiparticle interference on a type-II Weyl semimetal surface
Hao Zheng, Guang Bian, Guoqing Chang +15
We combine quasiparticle interference simulation (theory) and atomic resolution scanning tunneling spectro-microscopy (experiment) to visualize the interference patterns on a type-…
Emergent Quantum-Geometric Equivalence of Injection and Shift Currents
Mohammad Yahyavi, Tay-Rong Chang, Md Shafayat Hossain +3
Injection and shift currents are generally regarded as distinct nonlinear optical responses with separate microscopic origins. Here, we uncover a general hidden connection between…
Fermi Surface Topology and Hotspots Distribution in Kondo Lattice System CeB6
Madhab Neupane, Nasser Alidoust, Guang Bian +13
We present high-resolution angle-resolved photoemission spectroscopy studies of trivalent CeB6 and divalent BaB6 rare-earth hexaborides. We find that the Fermi surface electronic s…
Room-temperature nanoseconds spin relaxation in WTe2 and MoTe2 thin films
Qisheng Wang, Jie Li, Jean Besbas +11
The Weyl semimetal WTe2 and MoTe2 show great potential in generating large spin currents since they possess topologically-protected spin-polarized states and can carry a very large…
Theoretical prediction of magnetic and noncentrosymmetric Weyl fermion semimetal states in the R-Al-X family of compounds (R=rare earth, Al=aluminium, X=Si, Ge)
Guoqing Chang, Bahadur Singh, Su-Yang Xu +18
Weyl semimetals are novel topological conductors that host Weyl fermions as emergent quasiparticles. While the Weyl fermions in high-energy physics are strictly defined as the mass…
Topological Nature of Orbital Chern Insulators
Yueh-Ting Yao, Chia-Hung Chu, Arun Bansil +2
Ground state topologies in quantum materials have unveiled many unique topological phases with novel Hall responses. Recently, the orbital Hall effect in insulators has suggested t…
New fermions on the line in topological symmorphic metals
Guoqing Chang, Su-Yang Xu, Shin-Ming Huang +13
Topological metals and semimetals (TMs) have recently drawn significant interest. These materials give rise to condensed matter realizations of many important concepts in high-ener…
Spin correlated electronic state on the surface of a spin-orbit Mott system (Layered Iridates)
Chang Liu, Su-Yang Xu, Nasser Alidoust +13
Novel phases of two dimensional electron systems resulting from new surface or interface modified electronic structures have generated significant interest in material science. We…
Type-II Topological Dirac Semimetals: Theory and Materials Prediction (VAl3 family)
Tay-Rong Chang, Su-Yang Xu, Daniel S. Sanchez +13
The discoveries of Dirac and Weyl semimetal states in spin-orbit compounds led to the realizations of elementary particle analogs in table-top experiments. In this paper, we propos…
Moving Protocol of Majorana Corner Modes in a Superconducting 2D Weyl Semimetal Heterostructure
Ching-Kai Chiu, Yueh-Ting Yao, Tay-Rong Chang +1
Second-order topological superconductors host Majorana corner modes (MCMs), which are confined to specific corners of the system. This spatial restriction presents challenges for m…
Fermion-boson many-body interplay in a frustrated kagome paramagnet
J. -X. Yin, Nana Shumiya, Sougata Mardanya +22
Kagome-net, appearing in areas of fundamental physics, materials, photonic and cold-atom systems, hosts frustrated fermionic and bosonic excitations. However, it is extremely rare…
Field-free platform for topological zero-energy mode in superconductors LiFeAs and PbTaSe
Songtian S. Zhang, Jia-Xin Yin, Guangyang Dai +22
Superconducting materials exhibiting topological properties are emerging as an exciting platform to realize fundamentally new excitations from topological quantum states of matter.…
Two distinct topological phases in the mixed valence compound YbB6 and its differences from SmB6
Tay-Rong Chang, Tanmoy Das, Peng-Jen Chen +6
We discuss the evolution of topological states and their orbital textures in the mixed valence compounds SmB6 and YbB6 within the framework of the generalized gradient approximatio…
Electrically switchable Berry curvature dipole in the monolayer topological insulator WTe2
Su-Yang Xu, Qiong Ma, Huitao Shen +16
Recent experimental evidence for the quantum spin Hall (QSH) state in monolayer WTe has bridged two of the most active fields of condensed matter physics, 2D materials and topo…
Quasiparticle interference on cubic perovskite oxide surfaces
Yoshinori Okada, Tay-Rong Chang, Guoqing Chang +7
We report the first observation of coherent surface states on cubic perovskite oxide SrVO3(001) thin films through spectroscopic imaging scanning tunneling microscopy. A direct lin…
A minimal, "hydrogen atom" version of an inversion-breaking Weyl semimetal
Ilya Belopolski, Peng Yu, Daniel S. Sanchez +15
The recent explosion of research interest in Weyl semimetals has led to many proposed Weyl semimetal candidates and a few experimental observations of a Weyl semimetal in real mate…
Discovery of charge order and corresponding edge state in kagome magnet FeGe
Jia-Xin Yin, Yu-Xiao Jiang, Xiaokun Teng +21
Kagome materials often host exotic quantum phases, including spin liquids, Chern gap, charge order, and superconductivity. Existing scanning microscopy studies of the kagome charge…
Saddle-point von Hove singularity and dual topological insulator state in PtHgSe
Barun Ghosh, Sougata Mardanya, Bahadur Singh +7
Saddle-point van Hove singularities in the topological surface states are interesting because they can provide a new pathway for accessing exotic correlated phenomena in topologica…
Single crystal growth and physical property characterization of PbTaSe2 as a noncentrosymmetric type-II superconductor
Raman Sankar, G. Narsinga Rao, I. Panneer Muthuselvam +11
The single crystal growth and superconducting properties of PbTaSe2 with non-centrosymmetric crystal structure is reported. Using the chemical vapor transport (CVT) technique, PbTa…
Observation of surface states derived from topological Fermi arcs in the Weyl semimetal NbP
Ilya Belopolski, Su-Yang Xu, Daniel Sanchez +16
The recent experimental discovery of a Weyl semimetal in TaAs provides the first observation of a Weyl fermion in nature and demonstrates a novel type of anomalous surface state ba…
Two-dimensional MX family of Dirac materials with tunable electronic and topological properties
Yan-Fang Zhang, Jinbo Pan, Huta Banjade +6
We propose a novel class of two-dimensional (2D) Dirac materials in the MX family (M=Be, Mg, Zn and Cd, X = Cl, Br and I), which exhibit graphene-like band structures with linearly…
Relativistic horizon of interacting Weyl fermions in condensed matter systems
Wei-Chi Chiu, Guoqing Chang, Gennevieve Macam +12
The intersections of topology, geometry and strong correlations offer many opportunities for exotic quantum phases to emerge in condensed matter systems. Weyl fermions, in particul…
Quantum oscillations in the non-centrosymmetric superconductor and topological nodal-line semimetal PbTaSe
Xitong Xu, Zhibo Kang, Tay-Rong Chang +6
We observed quantum oscillations in thermoelectric and magnetic torque signals in non-centrosymmetric superconductor PbTaSe. One oscillatory frequency stems from the orbits for…
Large-area and high-quality 2D transition metal telluride
Jiadong Zhou, Fucai Liu, Junhao Lin +24
Atomically thin transitional metal ditellurides like WTe2 and MoTe2 have triggered tremendous research interests because of their intrinsic nontrivial band structure. They are also…
Room-temperature quantum spin Hall edge state in a higher-order topological insulator BiBr
Nana Shumiya, Md Shafayat Hossain, Jia-Xin Yin +24
Room-temperature realization of macroscopic quantum phenomena is one of the major pursuits in fundamental physics. The quantum spin Hall state, a topological quantum phenomenon tha…
Topological Dirac States and Pairing Correlations in the Non-Centrosymmetric Superconductor PbTaSe2
Tay-Rong Chang, Peng-Jen Chen, Guang Bian +13
Superconductivity in topological band structures is a platform for many novel exotic quantum phenomena such as emergent supersymmetry. This potential nourishes the search for topol…
Criteria for directly detecting topological Fermi arcs in Weyl semimetals
Ilya Belopolski, Su-Yang Xu, Daniel Sanchez +16
The recent discovery of the first Weyl semimetal in TaAs provides the first observation of a Weyl fermion in nature and demonstrates a novel type of anomalous surface state, the Fe…
Electronic structure, spin-orbit coupling, and interlayer interaction in bulk MoS2 and WS2
Drew W. Latzke, Wentao Zhang, Aslihan Suslu +7
We present in-depth measurements of the electronic band structure of the transition-metal dichalcogenides (TMDs) MoS2 and WS2 using angle-resolved photoemission spectroscopy, with…
Large Fermi Arcs in Unconventional Weyl Semimetal RhSi
Guoqing Chang, Su-Yang Xu, Benjamin J. Wieder +8
The theoretical proposal of chiral fermions in topological semimetals has led to a significant effort towards their experimental realization. In particular, the Fermi surfaces of c…
Quantum metric non-linear Hall effect in an antiferromagnetic topological insulator thin-film EuSn2As2
Hung-Ju Tien, Hsin Lin, Liang Fu +1
The quantum geometric structure of electrons introduces fundamental insights into understanding quantum effects in materials. One notable manifestation is the non-linear Hall effec…
Transverse circular photogalvanic effect associated with Lorentz-violating Weyl fermions
Mohammad Yahyavi, Yuanjun Jin, Yilin Zhao +9
Nonlinear optical responses of quantum materials have recently undergone dramatic developments to unveil nontrivial geometry and topology. A remarkable example is the quantized lon…
Discovery of the topological surface state in a noncentrosymmetric superconductor BiPd
Madhab Neupane, Nasser Alidoust, Su-Yang Xu +9
Recently, noncentrosymmetric superconductor BiPd has attracted considerable research interest due to the possibility of being a topological superconductor. Here, we report a system…
Magnetically tunable Dirac and Weyl fermions in the Zintl materials family
Anan Bari Sarkar, Sougata Mardanya, Shin-Ming Huang +7
Recent classification efforts encompassing crystalline symmetries have revealed rich possibilities for solid-state systems to support a tapestry of exotic topological states. Howev…
Topological crystalline insulator states in the CaAs family
Xiaoting Zhou, Chuang-Han Hsu, Tay-Rong Chang +9
Topological crystalline insulators (TCI) are insulating electronic phases of matter with nontrivial topology originating from crystalline symmetries. Recent theoretical advances ha…
Observation of Unpinned Two-Dimensional Dirac States in Antimony Single Layers with Phosphorene Structure
Qiangsheng Lu, Matthew Snyder, Kyle Y. Chen +10
The discovery of graphene has stimulated enormous interest in two-dimensional (2D) electron gas with linear band structure. 2D Dirac materials possess many intriguing physical prop…
Signatures of the Adler-Bell-Jackiw chiral anomaly in a Weyl Fermion semimetal
Chenglong Zhang, Su-Yang Xu, Ilya Belopolski +20
Weyl semimetals provide the realization of Weyl fermions in solid-state physics. Among all the physical phenomena that are enabled by Weyl semimetals, the chiral anomaly is the mos…
Enhanced Anomalous Hall Effect in Magnetic Topological Semimetal CoSnInS
Huibin Zhou, Guoqing Chang, Guangqiang Wang +10
We study the anomalous Hall Effect (AHE) of single-crystalline CoSnInS over a large range of indium concentration x from 0 to 1. Their magnetization reduces pro…
Discovery of Lorentz-violating Weyl fermion semimetal state in LaAlGe materials
Su-Yang Xu, Nasser Alidoust, Guoqing Chang +18
We report theoretical and experimental discovery of Lorentz-violating Weyl fermion semimetal type-II state in the LaAlGe class of materials. Previously type-II Weyl state was predi…
Prediction of three-fold fermions in a nearly-ideal Dirac semimetal BaAgAs
Sougata Mardanya, Bahadur Singh, Shin-Ming Huang +5
Materials with triply-degenerate nodal points in their low-energy electronic spectrum produce crystalline-symmetry-enforced three-fold fermions, which conceptually lie between the…
Non-Kondo-like Electronic Structure in the Correlated Rare-Earth Hexaboride YbB
Madhab Neupane, Su-Yang Xu, Nasser Alidoust +11
We present angle-resolved photoemission studies on the rare-earth hexaboride YbB, which has recently been predicted to be a topological Kondo insulator. Our data do not agree w…
Highly Mobile Carriers in a Candidate of Quasi-Two-Dimensional Topological Semimetal AuTeBr
Zeji Wang, Shuyu Cheng, Tay-Rong Chang +12
We report the crystal and electronic structures of a non-centrosymmetric quasi-two-dimensional (2D), candidate of topological semimetal AuTe2Br. The Fermi surface of this layered c…
Observation of Gapped Topological Surface States and Isolated Surface Resonances in PdTe Ultrathin Films
Jacob Cook, Sougata Mardanya, Qiangsheng Lu +7
The superconductor PdTe is known to host bulk Dirac bands and topological surface states. The coexistence of superconductivity and topological surface states makes PdTe a p…
Spin polarization and texture of the Fermi arcs in the Weyl Fermion semimetal TaAs
Su-Yang Xu, Ilya Belopolski, Daniel S. Sanchez +25
A Weyl semimetal is a new state of matter that host Weyl fermions as quasiparticle excitations. The Weyl fermions at zero energy correspond to points of bulk band degeneracy, Weyl…
Generalized Peierls substitution for the tight-binding model of twisted multilayer graphene in a magnetic field
Thi-Nga Do, Po-Hsin Shih, Hsin Lin +3
We propose a generalized Peierls substitution method in conjunction with the tight-binding model to explore the magnetic quantization and quantum Hall effect in twisted multilayer…
Robust topological state against magnetic impurities observed in superconductor PbTaSe2
Daniel Multer, Jia-Xin Yin, Songtian S. Zhang +5
Magnetic impurities deposited on topological superconductor candidate PbTaSe2 can introduce a non-splitting zero-energy state inside the superconducting gap, which has been propose…
Quantum metric nonlinear Hall effect in a topological antiferromagnetic heterostructure
Anyuan Gao, Yu-Fei Liu, Jian-Xiang Qiu +28
Quantum geometry - the geometry of electron Bloch wavefunctions - is central to modern condensed matter physics. Due to the quantum nature, quantum geometry has two parts, the real…