A5065615811- Topological Materials and Phenomena
- Graphene research and applications
- Quantum and electron transport phenomena
- Magnetic properties of thin films
- Physics of Superconductivity and Magnetism
- Advanced Condensed Matter Physics
- 2D Materials and Applications
- Atomic and Subatomic Physics Research
- Magnetic Field Sensors Techniques
- Advanced battery technologies research
- Electronic and Structural Properties of Oxides
- Supercapacitor Materials and Fabrication
- stochastic dynamics and bifurcation
- Nonlinear Dynamics and Pattern Formation
- Iron-based superconductors research
- Quantum optics and atomic interactions
- Cancer Research and Treatments
- Advanced Battery Materials and Technologies
- Spectral Theory in Mathematical Physics
- Immune Cell Function and Interaction
- Computational Physics and Python Applications
- Surface and Thin Film Phenomena
- Ferroelectric and Piezoelectric Materials
- Digital Transformation in Industry
- Perovskite Materials and Applications
Pennsylvania State University
2020-2024
Johns Hopkins University
2023-2024
NIST Center for Neutron Research
2023
Oak Ridge National Laboratory
2023
National Institute of Standards and Technology
2023
Shanghai Maritime University
2023
Wuhan National Laboratory for Optoelectronics
2020-2022
Huazhong University of Science and Technology
2020-2022
Digital Research Alliance of Canada
2008
A quantum anomalous Hall (QAH) insulator coupled to an s-wave superconductor is predicted harbor a topological superconducting phase, the elementary excitations of which (i.e. Majorana fermions) can form qubits upon non-Abelian braiding operations. recent transport experiment interprets half-quantized two-terminal conductance plateau as presence chiral fermions in millimeter-size QAH-Nb hybrid structure. However, there are concerns about this interpretation because non-Majorana mechanisms...
Aqueous rechargeable zinc (Zn) metal batteries show great application prospects in grid-scale energy storage devices due to their good safety, low cost, and considerable density. However, the electrical topographical inhomogeneity caused by native passivation layer of metallic Zn foil leads inhomogeneous electrochemical plating stripping Zn, limited accessible area electrolyte regular electrode causes poor rate capability, which together hinder practical aqueous batteries. In this work, we...
Abstract The rapid discovery of two-dimensional (2D) van der Waals (vdW) quantum materials has led to heterostructures that integrate diverse functionalities such as topological phases, magnetism, and superconductivity. In this context, the epitaxial synthesis vdW with well-controlled interfaces is an attractive route towards wafer-scale platforms for systematically exploring fundamental properties fashioning proof-of-concept devices. Here, we use molecular beam epitaxy synthesize a...
For the welding cell in manufacturing process of large excavation motor arm workpieces, a system framework, based on digital twin robot cell, is proposed and constructed order to optimize robotic collaboration workstation with technology. automated combined actual process, physical entity was digitally modeled 3D, operating posture beats other data were updated real time, through real-time interactive drive, achieve synchronization faithful mapping virtual as well 3D visualization monitoring...
The interface between two different materials can show unexpected quantum phenomena. In this study, we used molecular beam epitaxy to synthesize heterostructures formed by stacking together magnetic materials, a ferromagnetic topological insulator (TI) and an antiferromagnetic iron chalcogenide (FeTe). We observed emergent interface-induced superconductivity in these demonstrated the co-occurrence of superconductivity, ferromagnetism, band structure TI layer-the three essential ingredients...
There is growing interest in using multiterminal Josephson junctions (MTJJs) as a platform to artificially emulate topological phases and investigate superconducting mechanisms such multiplet Cooper pairings. Current experimental signatures MTJJs have led conflicting interpretations of the salient features. In this work, we report collaborative theoretical investigation graphene-based four-terminal junctions. We observe resonant features differential resistance maps that resemble those...
We report spin-to-charge and charge-to-spin conversion at room temperature in heterostructure devices that interface an archetypal Dirac semimetal, Cd3As2, with a metallic ferromagnet, Ni0.80Fe0.20 (permalloy). The spin-charge interconversion is detected by both spin torque ferromagnetic resonance driven pumping. Analysis of the symmetric anti-symmetric components mixing voltage frequency power dependence pumping signal show behavior these processes consistent previously reported mechanisms...
Magnetic topological insulators (MTIs) host topologically protected edge states, but the role that these states play in electronic transport remains unclear. Using scanning superconducting quantum interference device (SQUID) microscopy, we performed local measurements of current distribution a anomalous Hall (QAH) insulator at large bias currents, where quantization conductivity tensor breaks down. We find bulk currents channel interior coexist with sample boundary. While position changes...
We have demonstrated a robust magnetic tunnel junction (MTJ) with resistance-area product RA=8 Ω—μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> that simultaneously satisfies the statistical requirements of high tunneling magnetoresistance TMR ≫ 15σ(R <inf xmlns:xlink="http://www.w3.org/1999/xlink">p</inf> ), write threshold spread σ(Vw)/≪Vw≫ ≪7.1%, breakdown-to-write voltage margin over 0.5V, read-induced disturbance rate below 10...
We report the measurement of efficient charge-to-spin conversion at room temperature in Weyl semimetal/ferromagnet heterostructures with both oxidized and pristine interfaces. Polycrystalline films semimetal, TaAs, are grown by molecular beam epitaxy on (001) GaAs interfaced a metallic ferromagnet (Ni$_{0.8}$Fe$_{0.2}$). Spin torque ferromagnetic resonance (ST-FMR) measurements samples an interface yield spin efficiency as large $\xi_{\mathrm{FMR}}=0.45\pm 0.25$ for 8 nm Ni$_{0.8}$Fe$_{0.2}$...
We investigate the integer quantum Hall effect in Cd3As2 thin films under conditions of strong to moderate confinement (thicknesses 10 nm, 12 15 nm). In all films, we observe spin-polarized lowest Landau level (filling factor {\nu} = 1) and at spin-degenerate higher index levels with even filling factors ({\nu} 2,4,6). With increasing confinement, also a lifting spin degeneracy 3, manifest as emergence an anomaly longitudinal resistivity. Tight-binding calculations show that enhanced...
The authors investigate here the energy and momentum relaxation in Dirac semimetal Cd${}_{3}$As${}_{2}$ using linear nonlinear terahertz spectroscopy. They find that temperature dependence of these rates is consistent with quasielastic phonon-electron scattering down to lowest temperatures measured. These findings highlight how semimetal's unique lattice dynamics, including its low thermal conductivity soft phonons, offers new insights into potential applications for electronic...
Magnetic doping of topological quantum materials provides an attractive route for studying the effects time-reversal symmetry breaking. Thus motivated, we explore introduction transition metal Mn into thin films Dirac semimetal Cd3As2 during growth by molecular beam epitaxy. Scanning transmission electron microscopy measurements show formation a Mn-rich phase at top surface Mn-doped grown using both uniform and delta doping. This suggests that acts as surfactant epitaxial Cd3As2, resulting...
Time-reversal invariance (TRS) and inversion symmetry (IS) are responsible for the topological band structure in Dirac semimetals (DSMs). These symmetries can be broken by applying an external magnetic or electric field, resulting fundamental changes to ground state Hamiltonian a phase transition. We probe these using universal conductance fluctuations (UCF) prototypical DSM, Cd3As2. With increasing magnitude of UCF decreases factor 2, agreement with numerical calculations effect TRS. In...
We use magnetotransport in dual-gated magnetic topological insulator heterostructures to map out a phase diagram of the Hall and quantum anomalous effects as function chemical potential (primarily determined by back gate voltage) asymmetric top voltage). A theoretical model that includes both surface states valence band well allows evaluation variation Dzyaloshinskii-Moriya interaction carrier density with voltages. The qualitative agreement between experiment theory provides strong evidence...
We have used a combination of linear response time-domain THz spectroscopy (TDTS) and high-field non-linear to separately probe the electronic momentum energy relaxation rates respectively Dirac semimetal Cd$_3$As$_2$. find, consistent with prior measurements, that Cd$_3$As$_2$ has an enormous nonlinearities in frequency range. extract rate using Drude fits optical conductivity. also conduct range 2D coherent spectroscopy. The dominant is pump-probe signal, which allow us rate. find...
Breaking time-reversal symmetry in a Dirac semimetal ${\mathrm{Cd}}_{3}{\mathrm{As}}_{2}$ through doping with magnetic ions or by the proximity effect is expected to cause transition other topological phases (such as Weyl semimetal). To this end, we investigate possibility of proximity-induced ferromagnetic ordering epitaxial (${\mathrm{Cd}}_{3}{\mathrm{As}}_{2}$)/ferromagnetic semiconductor (${\mathrm{Ga}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}\mathrm{Sb}$) heterostructures grown molecular...