A5056425742- Magnetic properties of thin films
- Quantum and electron transport phenomena
- Magnetic and transport properties of perovskites and related materials
- Physics of Superconductivity and Magnetism
- Topological Materials and Phenomena
- ZnO doping and properties
- Magnetic Field Sensors Techniques
- Semiconductor Quantum Structures and Devices
- Magnetic Properties and Applications
- Magnetic Properties of Alloys
- Heusler alloys: electronic and magnetic properties
- Advanced Condensed Matter Physics
- Multiferroics and related materials
- Theoretical and Computational Physics
- Electronic and Structural Properties of Oxides
- Magnetic confinement fusion research
- 2D Materials and Applications
- Magneto-Optical Properties and Applications
- Atomic and Subatomic Physics Research
- Advancements in Semiconductor Devices and Circuit Design
- Advanced Chemical Physics Studies
- Thermal Regulation in Medicine
- Superconducting Materials and Applications
- Terahertz technology and applications
- Surface and Thin Film Phenomena
Czech Academy of Sciences, Institute of Physics
2016-2025
Czech Academy of Sciences
2005-2023
Charles University
2022
University at Buffalo, State University of New York
2012-2014
Akademie (Czechia)
2006-2009
Universität Hamburg
2002-2007
Palacký University Olomouc
1994
We predict that a lateral electrical current in antiferromagnets can induce non-equilibrium N\'eel order fields, i.e. fields whose sign alternates between the spin sublattices, which trigger ultra-fast spin-axis reorientation. Based on microscopic transport theory calculations we identify staggered current-induced analogous to intra-band and intrinsic inter-band spin-orbit previously reported ferromagnets with broken inversion-symmetry crystal. To illustrate their rich physics utility,...
Electrical spin-current generation is among the core phenomena driving field of spintronics. Using {\em ab initio} calculations we show that a room-temperature metallic collinear antiferromagnet RuO$_2$ allows for highly efficient generation, arising from anisotropically-split bands with conserved up and down spins along N\'eel vector axis. The zero net moment acts as an electrical spin-splitter 34$^\circ$ propagation angle between spin-up spin-down currents. Correspondingly,...
Abstract Commercial magnetic memories rely on the bistability of ordered spins in ferromagnetic materials. Recently, experimental bistable have been realized using fully compensated antiferromagnetic metals. Here we demonstrate a multiple-stable memory device epitaxial MnTe, an counterpart common II–VI semiconductors. Favourable micromagnetic characteristics MnTe allow us to smoothly varying zero-field anisotropic magnetoresistance (AMR) with harmonic angular dependence writing field angle,...
Altermagnetism is a recently identified magnetic symmetry class combining characteristics of conventional collinear ferromagnets and antiferromagnets, that were regarded as mutually exclusive, enabling phenomena functionalities unparalleled in either the two traditional elementary classes. In this work we use symmetry, ab initio theory, experiments to explore x-ray circular dichroism (XMCD) altermagnetic class. As representative material for our XMCD study choose α-MnTe with compensated...
We observe a singularity in the temperature derivative drho/dT of resistivity at Curie point high-quality (Ga,Mn)As ferromagnetic semiconductors with Tc's ranging from approximately 80 to 185 K. The character anomaly is sharply distinct critical contribution transport conventional dense-moment magnetic and reminiscent transition metal ferromagnets. Within region accessible our experiments, dependence on side can be explained by dominant scattering uncorrelated spin fluctuations. singular...
In various material systems, an antiferromagnetic phase was found to coexist with a weak ferromagneticlike signal, while symmetry-based theoretical predictions indicate possibility of nonzero anomalous Hall effect (AHE) even in the absence sample magnetization. This is case nominally collinear antiferromagnets, particular, hexagonal MnTe, where AHE and no detectable magnetization have been recently reported. To clarify role magnetization, we present study bulk MnTe samples, combining...
Altermagnetic (AM) materials exhibit non-relativistic, momentum-dependent spin-split states, ushering in new opportunities for spin electronic devices. While the characteristics of spin-splitting are documented within framework non-relativistic group symmetry, there is limited exploration inclusion relativistic symmetry and its impact on emergence a novel band structure. This study delves into intricate structure an AM material, α-MnTe. Employing temperature-dependent angle-resolved...
Our experimental and theoretical study of the non-crystalline crystalline components anisotropic magnetoresistance (AMR) in (Ga,Mn)As is aimed at exploring basic physical aspects this relativistic transport effect. The AMR reflects lifetimes holes due to polarized Mn impurities while associated with valence band warping. We find that sign determined by form spin-orbit coupling host relative strengths non-magnetic magnetic contributions impurity potential. develop methods directly yielding...
We demonstrate voltage control of the magnetic anisotropy a (Ga,Mn)As device bonded to piezoelectric transducer. The application uniaxial strain leads large reorientation easy axis, which is detected by anisotropic magnetoresistance measurements. Calculations based on mean-field kinetic-exchange model provide microscopic understanding measured effect. reported smooth in-plane anisotropy, electrically induced magnetization switching, and detection unconventional crystalline components...
Intraband and interband contributions to the current-driven spin-orbit torque in magnetic materials lacking inversion symmetry are theoretically studied using Kubo formula. In addition fieldlike ${\mathbf{T}}_{\mathrm{FL}}={\ensuremath{\tau}}_{\mathrm{FL}}\mathbf{m}\ifmmode\times\else\texttimes\fi{}{\mathbf{u}}_{\mathrm{so}}$ (${\mathbf{u}}_{\mathrm{so}}$ being a unit vector determined by of coupling), we explore intrinsic contribution arising from impurity-independent transitions producing...
Antiferromagnetic hexagonal MnTe is a promising material for spintronic devices relying on the control of antiferromagnetic domain orientations. Here we report neutron diffraction, magnetotransport, and magnetometry experiments semiconducting epitaxial thin films together with density functional theory (DFT) calculations magnetic anisotropies. The easy axes moments within basal plane are determined to be along $\ensuremath{\langle}1\overline{1}00\ensuremath{\rangle}$ directions. spin-flop...
The interest in understanding scaling limits of magnetic textures such as domain walls spans the entire field magnetism from its relativistic quantum fundamentals to applications information technologies. traditional focus on ferromagnets has recently started shift towards antiferromagnets which offer a rich materials landscape and utility ultra-fast neuromorphic devices insensitive perturbations. Here we report observation that an epitaxial crystal antiferromagnetic CuMnAs can be atomically...
Cyclotron resonance has been measured in far-infrared transmission of GaAs/Al$_x$Ga$_{1-x}$As heterostructures with an etched hexagonal lateral superlattice. Non-linear dependence the position on magnetic field was observed as well its splitting into several modes. Our explanation, based a perturbative calculation, describes phenomena weak effect potential two-dimensional electron gas. Using this approach, we found correlation between parameters patterning and created effective obtain thus...
In magnetic metals, electrical resistance depends on the direction of magnetization relative to current. New experiments show that this effect does not depend solely electron collisions, as is typically assumed.
An effective model of the hexagonal (NiAs-structure) manganese telluride valence band in vicinity $A$ point Brillouin zone is derived. It shown that whereas for usual antiferromagnetic order (magnetic moments on basal plane) splitting at small, their out-of-plane rotation enhances dramatically (to about 0.5 eV). We propose extensions recent experiments [Phys. Rev. Mater. 6, 014404 (2022)] where such inversion magnetocrystalline anisotropy has been observed Li-doped MnTe to confirm this...
Recently, MnTe was established as an altermagnetic material that hosts spin-polarized electronic bands well anomalous transport effects like the Hall effect. In addition to these arising from altermagnetism, also other magnetoresistance effects. Here, we study manipulation of magnetic order by applied field and its impact on electrical resistivity. particular, establish which components anisotropic are present when is rotated within hexagonal basal plane. Our experimental results, in...
Anisotropic magnetoresistance (AMR) is a relativistic magnetotransport phenomenon arising from combined effects of spin-orbit coupling and broken symmetry ferromagnetically ordered state the system. In this work we focus on one realization AMR in which enters via specific spin-textures carrier Fermi surfaces ferromagnetism elastic scattering carriers polarized magnetic impurities. We report detailed heuristic examination, using model coupled systems, emergence positive (maximum resistivity...
We present a procedure for finding the exact solution to linear-response Boltzmann equation two-dimensional anisotropic systems and demonstrate it on examples of noncrystalline magnetoresistance in system with spin-orbit interaction. show that two decoupled integral equations must be solved order find nonequilibrium distribution function up linear applied electric field. The are all based Rashba charged magnetic scatterers, where can evaluated analytically. Exact results compared earlier...
The large saturation magnetization in conventional dense moment ferromagnets offers a flexible means of manipulating the ordered state through demagnetizing shape anisotropy fields, but these dipolar turn, limit integrability magnetic elements information storage devices. We show that (Ga,Mn)As dilute-moment ferromagnet, with comparatively weaker dipole interactions, locally tunable magnetocrystalline can take role internal field which determines configuration. Experiments and theoretical...
It has been demonstrated that magnetocrystalline anisotropies in (Ga,Mn)As are sensitive to lattice strains as small 10^-4 and strain can be controlled by parameter engineering during growth, through post growth lithography, electrically bonding the sample a piezoelectric transducer. In this work we show analogous effects observed crystalline components of anisotropic magnetoresistance (AMR). Lithographically or induced variations produce AMR which larger than significant fraction total...
We present a study of transport in multiple-band noninteracting Fermi metallic systems based on the Keldysh formalism and self-consistent $T$-matrix approximation (TMA) taking into account effects Berry curvature due to spin-orbit coupling. apply this Rashba two-dimensional electron-gas ferromagnet calculate anomalous Hall effect (AHE) anisotropic magnetoresistance (AMR). The numerical calculations AHE reproduce analytical results regime revealing crossover between skew-scattering mechanism...
The Edelstein effect is the origin of spin-orbit torque: a current-induced torque that used for electrical control ferromagnetic and antiferromagnetic materials. This originates from relativistic coupling, which necessitates utilizing materials with heavy elements. Here, we show in magnetic non-collinear order, and, consequently, can exist even absence coupling. Using group symmetry analysis, model calculations, realistic simulations on selected compounds, identify large classes magnet...