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Condensed Matter Physics Commons™

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2021

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Articles 121 - 125 of 125

Full-Text Articles in Condensed Matter Physics

Reversal Of The Magnetoelectric Effect At A Ferromagnetic Metal/Ferroelectric Hfo2 Interface Induced By Metal Oxidation, Zhaojin Chen, Qiong Yang, Lingling Tao, Evgeny Y. Tsymbal Jan 2021

Reversal Of The Magnetoelectric Effect At A Ferromagnetic Metal/Ferroelectric Hfo2 Interface Induced By Metal Oxidation, Zhaojin Chen, Qiong Yang, Lingling Tao, Evgeny Y. Tsymbal

Evgeny Tsymbal Publications

Multiferroic materials composed of ferromagnetic and ferroelectric components are interesting for technological applications due to sizable magnetoelectric coupling allowing the control of magnetic properties by electric fields. Due to being compatible with the silicon-based technology, HfO2-based ferroelectrics could serve as a promising component in the composite multiferroics. Recently, a strong charge-mediated magnetoelectric coupling has been predicted for a Ni/HfO2 multiferroic heterostructure. Here, using density functional theory calculations, we systematically study the effects of the interfacial oxygen stoichiometry relevant to experiments on the magnetoelectric effect at the Ni/HfO2 interface. We demonstrate that the magnetoelectric effect is very …


Regular And In-Plane Skyrmions And Antiskyrmions From Boundary Instabilities, Shane Sandhoefner, Aldo Raeliarijaona, Rabindra Nepal, Dalton Snyder-Tinoco, Alexey Kovalev Jan 2021

Regular And In-Plane Skyrmions And Antiskyrmions From Boundary Instabilities, Shane Sandhoefner, Aldo Raeliarijaona, Rabindra Nepal, Dalton Snyder-Tinoco, Alexey Kovalev

Department of Physics and Astronomy: Faculty Publications

We formulate a theory of skyrmion and antiskyrmion generation using magnetic field and charge current pulses. We show that the topological defect can be created at an edge of a system with Dzyaloshinskii-Moriya interaction (DMI) as well as at a boundary between regions with different DMI. We consider both perpendicular and in-plane (also known as magnetic bimerons) versions of skyrmions and antiskyrmions. We show that the magnetization twist in the vicinity of an edge or a boundary is described by a kink solution, the presence of which can instigate the generation of topological defects. We study the collective excitations of …


Spin Superfluidity In Noncollinear Antiferromagnets, Bo Li, Alexey Kovalev Jan 2021

Spin Superfluidity In Noncollinear Antiferromagnets, Bo Li, Alexey Kovalev

Alexey Kovalev Papers

We explore the spin superfluid transport in exchange interaction-dominated three-sublattice antiferromagnets. The system in the long-wavelength regime is described by an SO(3) invariant field theory. Additional corrections from Dzyaloshinskii-Moriya interactions or anisotropies can break the symmetry; however, the system still approximately holds a U(1)-rotation symmetry. Thus, the power-law spatial decay signature of spin superfluidity is identified in a nonlocal-measurement setup where the spin injection is described by the generalized spin-mixing conductance. We suggest iron jarosites as promising material candidates for realizing our proposal.


Spirals And Skyrmions In Antiferromagnetic Triangular Lattices, Wuzhang Fang, Aldo Raeliarijaona, Po-Hao Chang, Alexey Kovalev, K. D. Belashchenko Jan 2021

Spirals And Skyrmions In Antiferromagnetic Triangular Lattices, Wuzhang Fang, Aldo Raeliarijaona, Po-Hao Chang, Alexey Kovalev, K. D. Belashchenko

Alexey Kovalev Papers

We study realizations of spirals and skyrmions in two-dimensional antiferromagnets with a triangular lattice on an inversion-symmetry-breaking substrate. As a possible material realization, we investigate the adsorption of transition-metal atoms (Cr, Mn, Fe, or Co) on a monolayer of MoS2, WS2, or WSe2 and obtain the exchange, anisotropy, and Dzyaloshinskii-Moriya interaction parameters using first-principles calculations. Using energy minimization and parallel-tempering Monte Carlo simulations, we determine the magnetic phase diagrams for a wide range of interaction parameters. We find that skyrmion lattices can appear even with weak Dzyaloshinskii-Moriya interactions, but their stability is hindered by magnetic anisotropy. However, a weak easy …


Thermally Driven Topology And The Topological Hall Effect In Chiral Magnets, Tan Dao Jan 2021

Thermally Driven Topology And The Topological Hall Effect In Chiral Magnets, Tan Dao

Honors Theses and Capstones

No abstract provided.