CrSb is a layered antiferromagnet (AFM) with perpendicular magnetic anisotropy, a high Néel temperature, and large spin-orbit coupling (SOC), which makes it interesting for AFM spintronic applications. To elucidate the various mechanisms of Néel vector control, the effects of strain, band filling, and electric field on the magnetic anisotropy energy (MAE) of bulk and thin-film CrSb are determined and analysed using density functional theory. The MAE of the bulk crystal is large (1.2 meV per unit cell). Due to the significant ionic nature of the Cr-Sb bond, finite slabs are strongly affected by end termination. Truncation of the bulk crystal to a thin film with one surface terminated with Cr and the other surface terminated with Sb breaks inversion symmetry, creates a large charge dipole and average electric field across the film, and breaks spin degeneracy, such that the thin film becomes a ferrimagnet. The MAE is reduced such that its sign can be switched with realistic strain, and the large SOC gives rise to an intrinsic voltage controlled magnetic anisotropy (VCMA). A slab terminated on both faces with Cr remains a compensated AFM, but with the compensation occurring nonlocally between mirror symmetric Cr pairs. In-plane alignment of the moments is preferred, the magnitude of the MAE remains large, similar to that of the bulk, and it is relatively insensitive to filling.
We report measurements of antiferromagnetic resonances in the van der Waals easy-axis antiferromagnet CrSBr. The interlayer exchange field and magnetocrystalline anisotropy fields are comparable to laboratory magnetic fields, allowing a rich variety of gigahertz-frequency dynamical modes to be accessed. By mapping the resonance frequencies as a function of the magnitude and angle of applied magnetic field we identify the different regimes of antiferromagnetic dynamics. The spectra show good agreement with a Landau-Lifshitz model for two antiferromagnetically-coupled sublattices, accounting for…
The contribution of bulk and surface to the electrical resistance along crystallographic \textit{b}- and \textit{c}-axes as a function of crystal thickness gives evidence for a temperature independent surface states in an antiferromagnetic narrow-gap semiconductor CrSb$_{2}$. ARPES shows a clear electron-like pocket at $Γ$-$Z$ direction which is absent in the bulk band structure. First-principles calculations also confirm the existence of metallic surface states inside the bulk gap. Whereas combined experimental probes point to enhanced surface conduction similar to topological insulators, sur…
Magnetic van der Waals (vdW) materials offer a fantastic platform to investigate and exploit rich spin configurations stabilized in reduced dimensions. One tantalizing magnetic order is the interlayer antiferromagnetism in A-type vdW antiferromagnet, which may be effectively modified by the magnetic field, stacking order and thickness scaling. However, atomically revealing the interlayer spin orientation in the vdW antiferromagnet is highly challenging, because most of the material candidates exhibit an insulating ground state or instability in ambient conditions. Here, we report the layer-dep…
Ferromagnetism above 200 K in organic-ion intercalated CrSBr
CIC nanoGUNE（纳米技术联合研究中心）；UPV/EHU（巴斯克地区理工大学）；CSIC-UPV/EHU（西班牙国家科研委员会-巴斯克地区理工大学）；Izmir Institute of Technology（伊兹密尔理工大学）；IKERBASQUE（伊克尔巴斯基奎基金会）；Universitat de València（瓦伦西亚大学）
Electric-field-driven magnetic switching and tightly bound interlayer excitons in bilayer CrSBr
Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology（华中科技大学物理学院）；School of Physics and Technology, Wuhan University（武汉大学物理科学与技术学院）；National Institute for Material Science（日本国立材料研究所）
Spin-Chirality-Driven Bulk Photovoltaic Effect in van der Waals Magnet CrSBr
State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University（清华大学物理系低维量子物理国家重点实验室）；Frontier Science Center for Quantum Information（量子信息前沿科学中心）；RIKEN Center for Emergent Matter Science (CEMS)（理化学会新兴物质科学中心）；Graduate School of China Academy of Engineering Physics（中国工程物理研究院研究生院）；Institute for Advanced Study, Tsinghua University（清华大学高等研究院）
Two-dimensional (2D) materials can host stable, long-range magnetic phases in the presence of underlying magnetic anisotropy. The ability to realize the full potential of 2D magnets necessitates systematic investigation of the role of individual atomic layers and nanoscale inhomogeneity ($\textit{i.e.}$, strain) on the emergence and stability of both intra- and interlayer magnetic phases. Here, we report multifaceted spatial-dependent magnetism in few-layer CrSBr using magnetic force microscopy (MFM) and Monte Carlo-based magnetic simulations. We perform nanoscale visualization of the magnetic…
Bulk and surface excitons in the van der Waals magnet CrSBr: Magneto-optical studies to 55 tesla
National High Magnetic Field Laboratory, Los Alamos National Laboratory（国家强磁场实验室，洛斯阿拉莫斯国家实验室）；Kyung Hee University（庆熙大学）；University of Chemistry and Technology Prague（布拉格化工大学）；Graduate Center of the City University of New York（纽约市立大学研究生院）
Layer-Dependent Phonons, Excitons, and Magneto-Optical Phenomena in CrSBr: A Mini Review
National Center for Nanoscience and Technology（中国科学院国家纳米科学中心）；University of Chinese Academy of Sciences（中国科学院大学）；University of Warsaw（华沙大学）；CNRS–UGA–UPS–INSA–EMFL（法国国家科学研究中心-格勒诺布尔阿尔卑斯大学-图卢兹第三大学-INSA图卢兹-东洛林大学）；University of Sapienza（罗马第一大学）
Magnetic topological insulators such as Cr-doped (Bi,Sb)2Te3 provide a platform for the realization of versatile time-reversal symmetry-breaking physics. By constructing heterostructures with Néel order in an antiferromagnetic CrSb and magnetic topological order in Cr-doped (Bi,Sb)2Te3, we realize emergent interfacial magnetic phenomena which can be tailored through artificial structural engineering. Through deliberate geometrical design of heterostructures and superlattices, we demonstrate the use of antiferromagnetic exchange coupling in manipulating the magnetic properties of the topologica…
Dimension- and Facet-Dependent Altermagnetic Biferroics and Ferromagnetic Biferroics and Triferroics in CrSb
School of Physics Huazhong University of Science and Technology（华中科技大学物理学院）；Wuhan National High Magnetic Field Center Huazhong University of Science and Technology（华中科技大学武汉国家强磁场中心）
The magnetic tunnel junction (MTJ) is a backbone device for spintronics. Realizing next generation energy efficient MTJs will require operating mechanisms beyond the standard means of applying magnetic fields or large electrical currents. Here, we demonstrate a new concept for programmable MTJ operation via strain control of the magnetic states of CrSBr, a layered antiferromagnetic semiconductor used as the tunnel barrier. Switching the CrSBr from antiferromagnetic to ferromagnetic order generates a giant tunneling magnetoresistance ratio without external magnetic field at temperatures up to ~…
Layer- and Field-Dependent Magnetic Order in 2D CrSBr Revealed by Pulsed Nanocalorimetry
Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST（加泰罗尼亚纳米科学和纳米技术研究所）；Universitat Autònoma de Barcelona（巴塞罗那自治大学）；Université Catholique de Louvain (UCLouvain)（天主教鲁汶大学）；Institut de Microelectrònica de Barcelona (IMB-CNM-CSIC)（巴塞罗那微电子研究所）；Columbia University（哥伦比亚大学）；WEL Research Institute（WEL研究所）；National Institute for Materials Science（日本国立材料研究所）
We have grown single crystals of electron doping system Ca2-xLaxRuO4 (0.00 <= x <= 0.20) by a floating zone method. The first order metal/non-metal transition and canted antiferromagnetic ordering occur for 0.00 < x < 0.15, similar to those in the bandwidth controlled system Ca2-xSrxRuO4 (CSRO). However, comparing with CSRO, we found a rather different metallic ground state adjacent to the non-metallic ground state with canted antiferromagnetic order. Instead of short-range antiferromagnetic correlation found in CSRO (0.20 <= x < 0.50), the metallic ground state of the present system is charac…
We report first-principles calculations on antiferromagnetic spin ordering in graphene under biaxial strain. Using hybrid functional calculations, we found that semimetallic graphene sheets undergo a transition to antiferromagnetic insulators at a biaxial strain of 7.7% and that the band gap rapidly increases after the onset of this transition before reaching 0.9 eV at a biaxial strain of 12%. We examined the competition of the antiferromagnetic spin ordering with two-dimensional Peierls distortions upon biaxial strain, and found that the preceding antiferromagnetic insulator phase impedes the…
Using Schwinger-boson mean-field theory, we calculate the dynamic spin structure factor at low temperatures $0<T\ll J$ for the spin-$1/2$ antiferromagnetic Heisenberg kagome model, within the gapped $\mathbb{Z}_2$ spin liquid phase Ansatz. We find that the spectral gap rapidly fills with temperature, with robust low-energy spectral weight developing by a temperature of $Δ/3$, where the spin gap is $2Δ$ (i.e., $Δ$ is the spinon gap), before any appreciable rise in spinon density or change in zero-temperature mean-field parameters. This is due to deconfinement of spinons which leads to terms sup…
Splitting of electronic spectrum in paramagnetic phase of itinerant ferromagnets and altermagnets
Moscow Institute of Physics and Technology（莫斯科物理技术学院）；M. N. Mikheev Institute of Metal Physics of the Ural Branch of the Russian Academy of Sciences（俄罗斯科学院乌拉尔分校 M.N. 米凯耶夫金属物理研究所）
We study three-dimensional nodal line semimetals (NLSMs) with magnetic ordering and strong spin-orbit interaction. Two distinct classes of magnetic NLSMs are proposed. The first class is band-inversion NLSM where the accidental line node is induced by band inversion and locally protected by glide mirror plane and the combined time-reversal and inversion symmetries. This can be viewed as a trivial stacking of the two-dimensional antiferromagnetic Dirac semimetals. The second class is essential NLSM where the nodal features are filling-enforced by specific magnetic symmetry group. We further pro…
