A5029889514- Topological Materials and Phenomena
- Advanced Condensed Matter Physics
- Physics of Superconductivity and Magnetism
- Iron-based superconductors research
- Rare-earth and actinide compounds
- Quantum and electron transport phenomena
- Electronic and Structural Properties of Oxides
- Magnetic and transport properties of perovskites and related materials
- Graphene research and applications
- Quantum, superfluid, helium dynamics
- Cold Atom Physics and Bose-Einstein Condensates
- Magnetic properties of thin films
- Quantum many-body systems
- Strong Light-Matter Interactions
- Semiconductor Quantum Structures and Devices
- Atomic and Subatomic Physics Research
- Advanced Chemical Physics Studies
- Diamond and Carbon-based Materials Research
- High-pressure geophysics and materials
- 2D Materials and Applications
- Heusler alloys: electronic and magnetic properties
- Advanced Materials Characterization Techniques
- Crystallography and Radiation Phenomena
- Surface and Thin Film Phenomena
- Metallurgical Processes and Thermodynamics
Zhejiang University
2015-2025
University of Tennessee at Knoxville
2022-2024
Pennsylvania State University
2017-2024
Aalto University
2023-2024
University of California, San Diego
2019-2021
Kavli Institute for Theoretical Sciences
2018-2020
University of Chinese Academy of Sciences
2018-2020
Collaborative Innovation Center of Advanced Microstructures
2015-2017
Majorana fermion (MF) whose antiparticle is itself has been predicted in condensed matter systems. Signatures of the MFs have reported as zero energy modes various More definitive evidences are highly desired to verify existence MF. Very recently, theory induce spin selective Andreev reflection (SSAR), a novel magnetic property which can be used detect MFs. Here we report first observation SSAR from inside vortices Bi2Te3/NbSe2 hetero-structure, topological superconductivity was previously...
Abstract Finite-momentum Cooper pairing is an unconventional form of superconductivity that widely believed to require finite magnetization. Altermagnetism emerging magnetic phase with highly anisotropic spin-splitting specific symmetries, but zero net Here, we study in metallic altermagnets connected conventional s -wave superconductors. Remarkably, find the pairs induced acquire a center-of-mass momentum, despite magnetization system. This anomalous Cooper-pair momentum strongly depends on...
Altermagnetism, a kind of collinear magnetism that is characterized by momentum-dependent band and spin splitting without net magnetization, has recently attracted considerable interest. Finding altermagnetic materials with large near the Fermi level necessarily requires three-dimensional k-space mapping. While this crucial for spintronic applications emergent phenomena, it remains challenging. Here, using synchrotron-based angle-resolved photoemission spectroscopy (ARPES), spin-resolved...
The recently discovered superconductivity in Nd$_{1-x}$Sr$_x$NiO$_2$ provides a new opportunity for studying strongly correlated unconventional superconductivity. single-hole Ni$^+$ ($3d^9$) configuration the parent compound NdNiO$_2$ is similar to that of Cu$^{2+}$ cuprates. We suggest after doping, intra-orbital spin-singlet and inter-orbital spin-triplet double-hole (doublon) configurations Ni$^{2+}$ are competing, we construct two-band Hubbard model by including both $3d_{x^2-y^2}$...
Majorana zero modes (MZMs) have been predicted to exist in the topological insulator (TI)/superconductor (SC) heterostructure. Recent spin polarized scanning tunneling microscope (STM) experiment$^{1}$ has observed spin-polarization dependence of bias differential conductance at center vortex core, which may be attributed selective Andreev reflection, a novel property MZMs theoretically 1-dimensional nanowire$^{2}$. Here we consider helical electron system described by Rashba orbit coupling...
The interplay among topology, superconductivity, and magnetism promises to bring a plethora of exotic unintuitive behaviors in emergent quantum materials. family Fe-chalcogenide superconductors FeTexSe1–x are directly relevant this context due their intrinsic topological band structure, high-temperature unconventional pairing symmetry. Despite enormous promise expectation, the local magnetic properties remain largely unexplored, which prevents comprehensive understanding underlying material...
In materials, certain approximated symmetry operations can exist in a lower-order approximation of the effective model but are good enough to influence physical responses system, and these symmetries were recently dubbed ``quasisymmetries'' [Nat. Phys. 18, 813 (2022)]. this paper, we reveal hierarchy structure quasisymmetries corresponding nodal structures that they enforce via two different approaches perturbation expansions for chiral crystal material CoSi. first approach, treat...
We study the vortex bound states in three dimensional (3D) superconducting Dirac semimetals with time reversal symmetry. Assuming two points on kz-axis and bulk s-wave superconductivity, a quantum line parallel to z-direction, we find that has robust quasi-1D nodal phase. The phase stems from symmetry protected normal state bands, it can be characterized by topological index (\nu; n) at kz = 0 \pi, where \nu is Z2 invariant for 0D class-D system n Z class-A according Altland- Zirnbauer...
Crystalline symmetry is a defining factor of the electronic band topology in solids, where many-body interactions often induce spontaneous breaking symmetry. Superconductors lacking an inversion center are among best systems to study such effects or even achieve topological superconductivity. Here, we demonstrate that TRuSi materials (with T transition metal) belong this class. Their bulk normal states behave as three-dimensional Kramers nodal-line semimetals, characterized by large...
Abstract Ferromagnetism and superconductivity are two key ingredients for topological superconductors, which can serve as building blocks of fault-tolerant quantum computers. Adversely, ferromagnetism typically also hostile orderings competing to align spins in different configurations, thus making the material design experimental implementation extremely challenging. A single platform with concurrent is actively pursued. In this paper, we fabricate van der Waals Josephson junctions made...
Superconducting vortices are promising traps to confine non-Abelian Majorana quasi-particles. It has been widely believed that bulk-state topology, of either normal-state or superconducting ground-state wavefunctions, is crucial for enabling zero modes in solid-state systems. This common belief shaped two major search directions modes, intrinsic topological superconductors trivially materials. Here we show Majorana-carrying vortex not exclusive but can arise from topologically trivial...
We show that lattice dislocations of topological iron-based superconductors such as FeTe
A distinguishing characteristic of Josephson junctions (JJs) is their nonlinear current-voltage response, which fulfills the requirements for superconducting quantum computing. Achieving atomically sharp interfaces between superconductors and weak links in JJs can realize superconductivity proximity effect, advancing investigation intrinsic properties unconventional potential applications. Here, a contamination-free approach to fabricating planar using molecular beam epitaxy (MBE) presented....
We report magnetotransport studies of $\mathrm{InAs}/\mathrm{GaSb}$ bilayer quantum wells in a regime where the interlayer tunneling between electron and hole gases is suppressed. When chemical potential tuned close to charge neutrality point, we observe anomalous oscillations that are inversely periodic magnetic field have an extremely high frequency despite highly insulating they observed. The seemingly contradictory coexistence sheet resistance cannot be understood within single-particle...
In this Letter, we establish a new theoretical paradigm for vortex Majorana physics in the recently discovered topological iron-based superconductors (TFeSCs). While TFeSCs are widely accepted as an exemplar of insulators (TIs) with intrinsic $s$-wave superconductivity, our theory implies that such common belief could be oversimplified. Our main finding is normal-state bulk Dirac nodes, usually ignored TI-based theories TFeSCs, will play key role determining state topology. particular,...
In two-dimensional insulators with time-reversal (TR) symmetry, a nonzero local Berry curvature of low-energy massive Dirac fermions can give rise to nontrivial spin and charge responses, even though the integral over all occupied states is zero. this Letter, we present new effect induced by electronic curvature. By studying electron-phonon interactions in ${\mathrm{BaMnSb}}_{2}$, prototype material possessing two TR-related cones, find that electrons induce phonon angular momentum. The...
Interaction induced topological states remain one of the fascinating phases in condensed matter physics. The exciton condensate has recently sparked renewed interest due to discovery new candidate materials and its driving force realize exotic states. In this work, we explore orders high-order topology bilayer quantum spin Hall insulators find that excitonic corner can be realized by tuning gate magnetic field. When an in-plane Zeeman field is applied system, two or four boundary-obstructed...
Abstract Interference patterns provide direct measurement of coherent propagation matter waves in quantum systems. Superfluidity Bose–Einstein condensates excitons can enable long-range ballistic exciton and lead to emerging long-scale interference patterns. Indirect (IXs) are formed by electrons holes separated layers. The theory predicts that the reduced IX recombination enables superfluid over macroscopic distances. Here, we present dislocation-like phase singularities produced condensate...
Abstract Over the last decade, possibility of realizing topological superconductivity (TSC) has generated much excitement. TSC can be created in electronic systems where and superconducting orders coexist, motivating continued exploration candidate material platforms to this end. Here, we use molecular beam epitaxy (MBE) synthesize heterostructures that host emergent interfacial when a non-superconducting antiferromagnet (FeTe) is interfaced with insulator (TI) (Bi, Sb) 2 Te 3 . By...
Motivated by the recent discovery of quantized spin Hall effect in InAs/GaSb quantum wells [Du, Knez, Sullivan, and Du, Phys. Rev. Lett. 114, 096802 (2015)], we theoretically study effects in-plane magnetic field strain to quantization charge conductance using Landauer-$\mathrm{B}\stackrel{\ifmmode \ddot{}\else \"{}\fi{}}{\text{u}}\mathrm{tikker}$ formalism. Our theory predicts a robustness against up very high 20 T. We use disordered hopping term model show that may help conductance....