A5058167245- Magnetic properties of thin films
- Multiferroics and related materials
- Advanced Condensed Matter Physics
- Physics of Superconductivity and Magnetism
- Topological Materials and Phenomena
- Graphene research and applications
- Ferroelectric and Piezoelectric Materials
- Electronic and Structural Properties of Oxides
- 2D Materials and Applications
- Advanced Electron Microscopy Techniques and Applications
- Theoretical and Computational Physics
- Electron and X-Ray Spectroscopy Techniques
- Thermal properties of materials
- ZnO doping and properties
- Surface and Thin Film Phenomena
- Quantum many-body systems
- Semiconductor materials and devices
- Advancements in Battery Materials
- Metamaterials and Metasurfaces Applications
- Microbial Fuel Cells and Bioremediation
- Quantum, superfluid, helium dynamics
- Magneto-Optical Properties and Applications
- Crystallography and Radiation Phenomena
- Adhesion, Friction, and Surface Interactions
- Copper Interconnects and Reliability
Brookhaven National Laboratory
2016-2023
Stony Brook University
2013-2020
Abstract Néel skyrmions are of high interest due to their potential applications in a variety spintronic devices, currently accessible ultrathin heavy metal/ferromagnetic bilayers and multilayers with strong Dzyaloshinskii–Moriya interaction. Here we report on the direct imaging chiral spin structures including an exchange-coupled cobalt/palladium multilayer at room temperature Lorentz transmission electron microscopy, high-resolution technique previously suggested exhibit no skyrmion...
Two-dimensional (2D) van der Waals (vdW) materials show a range of profound physical properties that can be tailored through their incorporation in heterostructures and manipulated with external forces. The recent discovery long-range ferromagnetic order down to atomic layers provides an additional degree freedom engineering 2D heterostructure devices for spintronics, valleytronics, magnetic tunnel junction switches. Here, using direct imaging by cryo-Lorentz transmission electron microscopy...
Anderson localization in phonon heat conduction is observed GaAs/AlAs superlattices with ErAs nanodots.
Abstract Single-layer graphene has demonstrated remarkable electronic properties that are strongly influenced by interfacial bonding and break down for the lowest energy configuration of stacked layers (AB Bernal). Multilayer with relative rotations between carbon layers, known as turbostratic graphene, can effectively decouple states adjacent preserving similar to SLG. While growth AB Bernal through chemical vapor deposition been widely reported, we investigate on heteroepitaxial Ni(111)...
The three-dimensional structure of nanoscale topological spin textures stabilized by the Dzyaloshinskii-Moriya interaction is governed delicate competition between exchange, demagnetization, and anisotropy energies. quantification such through direct experimental methods crucial towards understanding fundamental physics associated with their ordering, as well manipulation in spintronic devices. Here, we extend Lorentz transmission electron microscopy technique to quantify mixed Bloch-Néel...
Chiral spin textures stabilized by the interfacial Dzyaloshinkii-Moriya interaction, such as skyrmions and homochiral domain walls, have been shown to exhibit qualities that make them attractive for their incorporation in a variety of spintronic devices. However, thicker multilayer films, mixed occur which an achiral Bloch component coexists with chiral N\'eel wall reduce demagnetization field at film surface. We show interlayer interaction can break degeneracy between chiralities. further...
Chiral magnets have recently emerged as hosts for topological spin textures and related transport phenomena, which can find use in next-generation spintronic devices. The coupling between structural chirality noncollinear magnetism is crucial the stabilization of complex structures such magnetic skyrmions. Most studies been focused on physical properties homochiral states favored by crystal growth absence long-ranged interactions domains opposite chirality. Therefore, effects high density...
The possible realization of dissipationless chiral edge current in a topological insulator/magnetic insulator heterostructure is based on the condition that magnetic proximity exchange coupling at interface dominated by Dirac surface states insulator. Here we report polarized neutron reflectometry observation Dirac-electron-mediated effect bulk-insulating $(\mathrm{B}{\mathrm{i}}_{0.2}\mathrm{S}{\mathrm{b}}_{0.8}{)}_{2}\mathrm{T}{\mathrm{e}}_{3}$/magnetic EuS heterostructure. We are able to...
Composition gradients, or dissimilar ferroelectric bilayers, demonstrate colossal electromechanical figures of merit attributed to the motion ferroelastic domain walls. Yet, mechanistic understanding polarization switching pathways that drive in these systems remains elusive. Here, crucial roles strain and electrostatic boundary conditions bilayer are revealed, which underpin their dynamics. Using situ electrical biasing transmission electron microscope (TEM), walls is investigated a...
Topologically nontrivial spin textures such as vortices, skyrmions, and monopoles are promising candidates information carriers for future quantum science. Their controlled manipulation including creation annihilation remains an important challenge toward practical applications further exploration of their emergent phenomena. Here, we report evolution the helical skyrmion phases in thin films multiferroic Te-doped Cu2OSeO3 a function material thickness, dopant, temperature, magnetic field...
Polar discontinuity at interfaces plays deterministic roles in charge transport, magnetism, and even superconductivity of functional oxides. To date, most polar problems have been explored heterointerfaces between two dissimilar materials. Here, we show that charged domain walls (CDWs) epitaxial thin films ferroelectric $\mathrm{PbZ}{\mathrm{r}}_{0.2}\mathrm{T}{\mathrm{i}}_{0.8}{\mathrm{O}}_{3}$ are strongly coupled to through the formation...
Ferromagnetism in two-dimensional (2D) materials provides an ideal platform to study emergent electromagnetic phenomena low dimensions for future spintronics. In magnetic-element intercalated transition metal dichalcogenides, topologically nontrivial spin textures, such as chiral helimagnetic states and soliton lattices, are realized due the lattice distortions induced by magnetic ions. Consequently, chirality is predictably determined sign of antisymmetric exchange interaction (or...
Electric field control of topologically nontrivial magnetic textures, such as skyrmions, provides a paradigm shift for future spintronics beyond the current silicon-based technology. While significant progress has been made by X-ray and neutron scattering studies, direct observation nanoscale spin structures their dynamics driven external electric fields remains challenge in understanding underlying mechanisms harness functionalities. Here, using Lorentz transmission electron microscopy...
Many-body localization (MBL) has attracted significant attention due to its immunity thermalization, role in logarithmic entanglement entropy growth, and opportunities reach exotic quantum orders. However, experimental realization of MBL solid-state systems remained challenging. Here we report evidence a possible phonon phase disordered GaAs/AlAs superlattices. Through grazing-incidence inelastic X-ray scattering, observe strong deviation the population from equilibrium samples doped with...
Bloch lines (BLs) play a key role in determining the static and dynamic behavior of chiral domain walls skyrmions multilayer films with significant Dzyaloshinskii-Moriya interaction (DMI). Here, using situ Lorentz phase microscopy, we reveal type spin texture termed type-II domain-wall pair (DWP), stabilized DMI thin BLs. For DWP, components each complementary wall are parallel, implying opposite chirality. We find that DWPs preferentially form through bifurcation type-I DWP require...
Journal Article Homochiral Skyrmionic Bubbles in Exfoliated 2D Van Der Waals Cr2Ge2Te6 Get access Myung-Geun Han, Han Brookhaven National Laboratory, Upton, New York, United States Search for other works by this author on: Oxford Academic Google Scholar Joseph Garlow, Garlow Yimei Zhu, Zhu Huiqin Zhang, Zhang University of Pennsylvania, Philadelphia, Yu Liu, Liu Donald DiMarzio, DiMarzio Northrop Grumman Corporation, Redondo Beach, California, Cedomir Petrovic, Petrovic Deep Jariwala...
Abstract not Available.
Journal Article Electrostatic Potential Mapping by Secondary-electron Voltage-contrast and Electron-beam-induced-current in TEM Get access Myung-Geun Han, Han Condensed Matter Physics & Materials Science, Brookhaven National Laboratory, Upton, NY, USA Search for other works this author on: Oxford Academic Google Scholar Joseph A Garlow, Garlow Science Engineering Department, Stony Brook University, Brook, Yimei Zhu Microscopy Microanalysis, Volume 23, Issue S1, 1 July 2017, Pages 1424–1425,...
Topologically nontrivial spin textures such as vortices, skyrmions, and monopoles are promising candidates information carriers for future quantum science [1].However, controlled skyrmion manipulation including creation annihilation remains an important challenge towards not only practical applications but also the full exploitation of their emergent properties behaviours.Recently, intriguing discovery a new phase [2] along with thermal-fluctuation-induced A-phase skyrmions has been made in...