When a coplanar antiferromagnet (AFM) with $xy$-plane magnetic moments exhibits a spin-split band structure and unidirectional spin polarization along $z$, the spin polarization is forced to be an odd function of momentum by the fundamental symmetry $[\bar{C}_{2z}\|\mathcal{T}]$. Coplanar AFMs displaying such odd-parity, unidirectionally polarized spin splittings are known as odd-parity magnets. In this work, we propose the realization of their missing even-parity counterparts. We begin by deriving the symmetry conditions required for an even-parity, out-of-plane spin splitting. We then show that irradiating a spin-degenerate coplanar AFM with circularly polarized light lifts the $[\bar{C}_{2z}\|\mathcal{T}]$ constraint, dynamically generating this even-parity state. Specifically, the light-induced unidirectionally polarized spin splitting exhibits a $d$-wave texture in momentum space, akin to that of a $d$-wave altermagnet. We prove this texture's robustness against spin canting and propose time-, spin- and angle-resolved photoemission photocurrent as a direct probe. Our work demonstrates that optical driving can generate novel spin-split phases in coplanar AFMs, thereby diversifying the landscape of materials exhibiting distinct spin splittings.
We investigate the performance of niobium nitride superconducting coplanar waveguide resonators towards hybrid quantum devices with magnon-photon coupling. We find internal quality factors ~ 20000 at 20 mK base temperature, in zero magnetic field. We find that by reducing film thickness below 100 nm internal quality factor greater than 1000 can be maintained up to parallel magnetic field of ~ 1 T and perpendicular magnetic field of ~ 100 mT. We further demonstrate strong coupling of microwave photons in these resonators, with magnons in chromium trichloride, a van der Waals antiferromagnet, wh…
Towards the First Realization of Weyl Magnons in the Non-Coplanar Antiferromagnet MnTe$_2$
The Ohio State University（俄亥俄州立大学）；National Institute of Standards and Technology（美国国家标准与技术研究院）；Oak Ridge National Laboratory（橡树岭国家实验室）；Duke University（杜克大学）
Taking the non-collinear antiferromagnetic hexagonal Heusler compound Mn$_3$Ge as a reference system, the contributions to linear response phenomena arising solely from the chiral coplanar and non-coplanar spin configurations are investigated. Orbital moments, X-ray absorption, anomalous and spin Hall effects, as well as corresponding spin-orbit torques and Edelstein polarizations are studied depending on a continuous variation of the polar angle relative to the Kagome planes of corner-sharing triangles between the non-collinear antiferromagnetic and the ferromagnetic limits. By scaling the sp…
The non-collinear antiferromagnetic (AFM) structure makes Mn3Sn exhibit exotic properties. At present, it has been found that both the hydrostatic pressure and the strain introduced by interstitial N atoms have a great influence on this magnetic structure. Here, the effect of the residual strain (RS) on it is investigated. AC and DC magnetic measurement results suggest that Mn3Sn without RS has the non-collinear AFM structure only in the temperature range of 285 K to 400 K; while Mn3Sn with RS has a non-coplanar AFM structure in the entire temperature range from 5 K to 400 K. Both anomalous Ha…
Competing magnetic states in a non-coplanar Kagome magnet
University of Cambridge（剑桥大学）；Institute of Physics, Polish Academy of Sciences（波兰科学院物理研究所）；University of Chinese Academy of Sciences（中国科学院大学）；American University of Sharjah（沙迦美国大学）；City University of Hong Kong（香港城市大学）；University of Salerno（萨莱诺大学）；University of Konstanz（康斯坦茨大学）；Department of Materials, University of Oxford（牛津大学材料系）；SPIN-CNR
We investigate the magnetism of a previously unexplored distorted spin-1/2 kagome model consisting of three symmetry-inequivalent nearest-neighbor antiferromagnetic Heisenberg couplings Jhexagon, J and J', and uncover a rich ground state phase diagram even at the classical level. Using analytical arguments and numerical techniques we identify a collinear Q = 0 magnetic phase, two unusual non-collinear coplanar Q = (1/3,1/3) phases and a classical spin liquid phase with a degenerate manifold of non-coplanar ground states, resembling the jammed spin liquid phase found in the context of a bond-di…
The anomalous Hall effect has been indispensable in our understanding of numerous magnetic phenomena. This concerns both ferromagnetic materials, as well as diverse classes of antiferromagnets, where in addition to the anomalous and crystal Hall effects, the topological Hall effect in non-coplanar antiferromagnets has been a subject of intensive research in the past decades. Here, we uncover a new flavour of the anomalous Hall effect in canted spin systems. Using advanced theoretical tools we demonstrate that upon canting, the anomalous Hall effect acquires a contribution which is sensitive to…
Predictions of the anisotropic magnetic susceptibility chi below the antiferromagnetic (AFM) ordering temperatures TN of local moment Heisenberg AFMs have been made previously using molecular field theory (MFT) but are very limited in their applicability. Here a MFT calculation of chi(T<=TN) is presented for a wide variety of collinear and noncollinear Heisenberg AFMs containing identical crystallographically equivalent spins without recourse to magnetic sublattices. The results are expressed in terms of directly measurable experimental parameters and are fitted with no adjustable parameters t…
Y{0.5}$Ca{0.5}BaCo4O7 contains kagome layers of Co ions, whose spins are strongly coupled according to a Curie-Weiss temperature of -2200 K. At low temperatures, T = 1.2 K, our diffuse neutron scattering study with polarization analysis reveals characteristic spin correlations close to a predicted two-dimensional coplanar ground state with staggered chirality. The absence of three dimensional long-range AF order proves negligible coupling between the kagome layers. The scattering intensities are consistent with high spin S=3/2 states of Co2+ in the kagome layers and low spin S=0 states for Co3…
A new type of magnetically frustrated lattice is found in the layered fluoride NaBa2Mn3F11. A kagome-type array of regular triangles composed of Mn2+ ions (spin 5/2) deforms so as to generate the next-nearest-neighbor interaction J2 between three out of six spins in the hexagon of a normal kagome lattice, in addition to the nearest-neighbor interaction J1. As a function of |J2/J1|, this lattice can interconnect the kagome (J2 = 0) and the triangular (J2 = J1) lattices and thus is called the kagome-triangular (KT) lattice. Magnetic susceptibility and heat capacity measurements performed on a po…
Plaid-Like Spin Splitting and Chirality of Magnon Bands in Antiferromagnetic MnTe$_2$
Sejong University（世宗大学）；Korea Advanced Institute of Science and Technology (KAIST)（韩国科学技术院）；Sungkyunkwan University（成均馆大学）；Institute of Physics, Academia Sinica（中央研究院物理研究所）
A spin-1 Heisenberg model on trimerized Kagomé lattice is studied by doing a low-energy bosonic theory in terms of plaquette-triplons defined on its triangular unit-cells. The model has an intra-triangle antiferromagnetic exchange interaction, $J$ (set to 1), and two inter-triangle couplings, $J^\prime>0$ (nearest-neighbor) and $J^{\prime\prime}$ (next-nearest-neighbor; of both signs). The triplon analysis of this model studies the stability of the trimerized singlet (TS) ground state in the $J^\prime$-$J^{\prime\prime}$ plane. It gives a quantum phase diagram that has two gapless antiferromag…
Entropy-driven phase transition in a non-collinear antiferromagnet due to higher-order exchange interactions
University of Kiel（基尔大学）；Université de Toulouse（图卢兹大学）；CNRS（法国国家科学研究中心）；University of Iceland（冰岛大学）；Kiel Nano, Surface, and Interface Science (KiNSIS)（基尔纳米、表面与界面科学研究所）
FeF$_3$, with its half-filled Fe$^{3+}$ $3d$ orbital, hence zero orbital angular momentum and $S=5/2$, is often put forward as a prototypical highly-frustrated classical Heisenberg pyrochlore antiferromagnet. By employing {\it ab initio} density functional theory (DFT), we obtain an effective spin Hamiltonian for this material. This Hamiltonian contains nearest-neighbor antiferromagnetic Heisenberg, bi-quadratic and Dzyaloshinskii-Moriya interactions as dominant terms and we use Monte Carlo simulations to investigate the nonzero temperature properties of this minimal model. We find that upon d…
Long-distance propagation of high-velocity antiferromagnetic spin waves
Fert Beijing Institute, MIIT Key Laboratory of Spintronics, School of Integrated Circuit Science and Engineering, Beihang University（北京航空航天大学集成电路科学与工程学院）；International Quantum Academy（国际量子科学院）；Department of Materials, ETH Zurich（苏黎世联邦理工学院材料系）；Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University（清华大学材料科学与工程系）；Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology（南方科技大学深圳量子科学与工程学院）
Anomalous Hall enhancement in fully compensated non-collinear antiferromagnetic Cr-doped Mn3Sn
National University of Singapore（新加坡国立大学）；National University of Singapore (Chongqing) Research Institute（新加坡国立大学（重庆）研究院）；Nanyang Technological University（南洋理工大学）；Nanjing University（南京大学）；Central South University（中南大学）
Vector Spin Chirality Switching in Noncollinear Antiferromagnets
Jawaharlal Nehru Centre for Advanced Scientific Research（贾瓦哈拉尔·尼赫鲁高级科学研究中心）；SASTRA Deemed University（萨斯特拉认定大学）；Deutsches Elektronen-Synchrotron (DESY)（德国电子同步加速器）；Indian Institute of Science Education and Research Thiruvananthapuram（印度科学教育研究所特里凡得琅分校）；UGC-DAE Consortium for Scientific Research（UGC-DAE科研联盟）；ALBA Synchrotron Light Source（阿尔巴同步辐射光源）；The University of Sydney（悉尼大学）；Indian Institute of Science Education and Research Bhopal（印度科学教育研究所博帕尔分校）
Tunable chiral and nematic states in the triple-Q antiferromagnet Co$_{1/3}$TaS$_2$
National High Magnetic Field Laboratory, Los Alamos National Lab（国家高磁场实验室，洛斯阿拉莫斯国家实验室）；Materials Science and Technology Division, Oak Ridge National Laboratory（橡树岭国家实验室材料科学与技术部）；Department of Physics and Astronomy, Seoul National University（首尔大学物理与天文学系）；Department of Physics and Astronomy, University of Tennessee, Knoxville（田纳西大学诺克斯维尔分校物理与天文学系）；Shull Wollan Center—A Joint Institute for Neutron Sciences, Oak Ridge National Laboratory（橡树岭国家实验室舒尔-沃兰中子科学联合研究所）；Institute of Applied Physics, Seoul National University（首尔大学应用物理研究所）
