A5091001877- Magnetic properties of thin films
- Topological Materials and Phenomena
- Advanced Condensed Matter Physics
- Graphene research and applications
- Theoretical and Computational Physics
- Atomic and Subatomic Physics Research
- Magnetic and transport properties of perovskites and related materials
- Characterization and Applications of Magnetic Nanoparticles
- Quantum many-body systems
- Electronic and Structural Properties of Oxides
- Magnetic Field Sensors Techniques
- Semiconductor materials and interfaces
- Smart Grid and Power Systems
- Quantum and electron transport phenomena
- 2D Materials and Applications
- Physics of Superconductivity and Magnetism
- Power Systems and Technologies
- Magneto-Optical Properties and Applications
- Multiferroics and related materials
- Cerebrovascular and Carotid Artery Diseases
- Chemical and Physical Properties of Materials
- Magnetic Properties and Applications
- Aerogels and thermal insulation
- Topological and Geometric Data Analysis
- Smart Grid Energy Management
Tsinghua University
2024
Inspire Institute
2024
University of California, Los Angeles
2016-2023
After the recognition of possibility to implement Majorana fermions using building blocks solid-state matters, detection this peculiar particle has been an intense focus research. Here we experimentally demonstrate a collection living in one-dimensional transport channel at boundary superconducting quantum anomalous Hall insulator thin film. A series topological phase changes are controlled by reversal magnetization, where half-integer quantized conductance plateau (0.5e2/h) is observed as...
Spin-momentum locked surface states in topological insulators (TIs) provide a promising route for achieving high spin-orbit torque (SOT) efficiency beyond the bulk coupling heavy metals (HMs). However, previous works, there is huge discrepancy among quantitative SOTs from TIs various systems determined by different methods. Here, we systematically study SOT TI(HM)/Ti/CoFeB/MgO same method, and make conclusive assessment of HMs. Our results demonstrate that show more than one order magnitude...
Geometric Hall effect is induced by the emergent gauge field experienced carriers adiabatically passing through certain real-space topological spin textures, which a probe to non-trivial such as magnetic skyrmions. We report experimental indications of spin-texture charges in heterostructures insulator (Bi,Sb)2Te3 coupled an antiferromagnet MnTe. Through seeding effect, pinned spins at interface leads tunable modification averaged charge. This experimentally manifests field-dependent...
Abstract All-electrical driven magnetization switching attracts much attention in next-generation spintronic memory and logic devices, particularly magnetic random-access (MRAM) based on the spin–orbit torque (SOT), i.e. SOT-MRAM, due to its advantages of low power consumption, fast write/read speed, improved endurance, etc. For conventional SOT-driven magnet with perpendicular anisotropy, an external assisted field is necessary break inversion symmetry magnet, which not only induces...
Ferromagnetism in topological insulators (TIs) opens a topologically non-trivial exchange band gap, providing an exciting platform to manipulate the order through external magnetic field. Here, we experimentally show that surface of antiferromagnetic thin film can independently control top and bottom states TI proximity couplings. During magnetization reversal field scan, two intermediate spin configurations stem from unsynchronized switchings AFM/TI interfaces. These are shown result new...
We use temperature-dependent Hall measurements to identify contributions of spin Hall, magnetic proximity, and sublattice effects the anomalous signal in heavy metal/ferrimagnetic insulator heterostructures with perpendicular anisotropy. This approach enables detection both proximity effect onset temperature magnetization compensation provides essential information regarding interfacial exchange coupling. Onset a yields local extremum signal, which occurs at higher as thickness increases....
Breaking the time reversal symmetry (TRS) in a topological insulator (TI) by introducing magnetic order gives rise to exotic quantum phenomena. One of promising routes inducing TI is utilizing proximity effect between and strong (MI). In this article, we demonstrate TI/MI heterostructure prepared through transferring molecular beam epitaxy (MBE)-grown Bi2Se3 film onto yttrium iron garnet (YIG) substrate via wet transfer. The transferred exhibits excellent quality over large scale. Moreover,...
Quantum anomalous Hall effect has been observed in magnetically doped topological insulators. However, full quantization, up until now, is limited within the sub-1 K temperature regime, although material's magnetic ordering can go beyond 100 K. Here, we study limiting factors of Cr-doped (BiSb)2Te3 systems using both transport and magneto-optical methods. By deliberate control thin-film thickness doping profile, revealed that low occurring quantum current material system a combined result...
The topological surface states (TSS) in insulators (TIs) can exert strong spin-orbit torque (SOT) on adjacent magnetization, offering great potential implementing energy-efficient magnetic memory devices. However, there are large discrepancies among the reported spin Hall angle values TIs, and its temperature dependence still remains elusive. Here, a modulation-doped Cr-Bix Sb2-x Te3 (Cr-BST) film is quantitatively determined via both transport optic approaches, where consistent results...
Integration of a quantum anomalous Hall insulator with magnetically ordered material provides an additional degree freedom through which the resulting exotic states can be controlled. Here, experimental observation is reported effect in magnetically-doped topological grown on antiferromagnetic Cr2 O3 . The exchange coupling between two materials investigated using field-cooling-dependent magnetometry and polarized neutron reflectometry. Both techniques reveal strong interfacial interaction...
Atomic termination plays a key role in activating the proximity effect of antiferromagnet.
Abstract The antiferromagnet (AFM) and ferromagnet (FM) interface is a unique branch of magnetics broad scientific interest. AFMs play an important role in spin‐orbit torque devices based on their ability to generate spin‐polarized current exchange bias when combined with FMs. In this study, interesting (SOT) ratchet involving the spring effect IrMn/CoFeB bilayer device perpendicular anisotropy developed. use electrical spectroscopic analysis reveals that yields unidirectional anisotropy,...
Abstract Recent advances in using topological insulators (TIs) with ferromagnets (FMs) at room temperature have opened an innovative avenue spin‐orbit torque (SOT) nonvolatile magnetic memory and low dissipation electronics. However, direct integration of TIs perpendicularly magnetized FM, while retaining extraordinary charge‐to‐spin conversion efficiency ( > 100%), remains a major challenge. In addition, the indispensable thermal compatibility modern CMOS technologies has not yet been...
Spin-orbit torque (SOT)-MRAM is a promising candidate for future nonvolatile memory technology. Finding materials that have large SOT efficiency <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\xi_{\text{DL}})$</tex> critical developing the SOT-MRAM. Topological insulators (TIs) been shown to exhibit giant xmlns:xlink="http://www.w3.org/1999/xlink">$\xi_{\text{DL}}$</tex> (>1) at room temperature. However, integration of high TIs with CoFeB...
Nonlinear unidirectional spin Hall magnetoresistance (USMR) has been reported in heavy metal/ferromagnet bilayers, which could be employed as an effective method detecting the magnetization orientation spintronic devices with two-terminal geometry. Recently, another (UMR) was magnetic topological insulator (TI)-based heterostructures at cryogenic temperature, whose amplitude is orders of magnitude larger than USMR measured metal-based room temperature. Here, we report UMR effect...
In multilayered magnetic topological insulator structures, magnetization reversal processes can drive phase transitions between quantum anomalous Hall, axion insulator, and normal states. Here we report an examination of the critical behavior two such transitions: Hall to (QAH-NI), (QAH-AXI) transitions. By introducing a new analysis protocol wherein temperature dependent variations in coercivity are accounted for, QAH-NI QAH-AXI evaluated over wide range field. Despite uniqueness these...
The emerging material, topological insulator, has provided new opportunities for spintronic applications, owing to its strong spin-orbit character. Topological insulator based heterostructures that display spin-charge coupling driven by topology at surfaces have great potential the realization of novel devices. Here, we report observation anomalous photogalvanic effect in (${\mathrm{Bi}}_{0.5}{\mathrm{Sb}}_{0.5}$)${}_{2}{\mathrm{Te}}_{3}$ thin films grown on GaAs substrate. We demonstrate...
Cd3As2 is a Dirac semimetal that 3D analog of graphene. We investigated the local structure and nuclear-spin dynamics in via 113Cd NMR. The wideline spectrum static sample at 295 K asymmetric its features are well described by two-site model with shielding parameters extracted Herzfeld-Berger analysis magic-angle spinning spectrum. Surprisingly, spin-lattice relaxation time (T1) extremely long (T1 = 95 s K), stark contrast to conductors effects native defects upon semiconductors; but it...
Heavy metals and topological insulators are promising materials for converting charge current into spin efficient manipulation of magnetization states in magnetic devices [1]–[5]. One the most important parameters is charge-to-spin conversion (CS) efficiency. Improving CS efficiency critical reducing write emerging nonvolatile memory technology, spin-orbit torque MRAM (SOT-MRAM) [2], which provides comparable speed with SRAM but a much higher capacity. Here, we measure various (TIs) using...
Interfacial quantum states are drawing tremendous attention recently because of their importance in design low-dimensional heterostructures with desired charge, spin, or topological properties. Although most studies the interfacial exchange interactions were mainly performed across interface vertically, lateral transport nowadays is still a major experimental method to probe these indirectly. In this Letter, we fabricated graphene and hydrogen passivated silicon study processes. For first...