Pal Sreya, Hasan Md Nur, Bangar Himanshu, Salehi Nastaran, Mathur Sayan, Pereiro Manuel, Thunström Patrik, Muduli Pranaba Kishor, Karmakar Debjani, Barman Anjan
Department of Condensed Matter and Materials Physics, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700106, India.
Department of Physics and Astronomy, Uppsala University, Box 516, SE-75120 Uppsala, Sweden.
ACS Nano. 2025 Jul 8;19(26):23564-23574. doi: 10.1021/acsnano.4c17187. Epub 2025 Jun 26.
Development of energy-efficient spintronics demands spin-orbit effects and chiral spin textures. The latter requires the Dzyaloshinskii-Moriya interaction (DMI) and its interplay with Heisenberg exchange. Understanding the relative strengths of Heisenberg exchange and interfacial DMI (iDMI) and its scaling with spin-orbit coupling (SOC) is key to stabilizing chiral spin textures in nonmagnet/ferromagnet heterostructures. Here, Brillouin light scattering (BLS) spectroscopy is employed to determine the iDMI and Heisenberg exchange stiffness constants for large-area chemical vapor-deposited monolayer two-dimensional (2D) transition-metal dichalcogenides (TMDs) (MoS, MoSe, WS, and WSe) interfaced with permalloy (Py) thin films. Both symmetric and antisymmetric exchange interactions exhibited a nearly identical dependence on SOC strength for all four interfaces. The origin of the interfacial exchange interaction is underpinned with the help of first-principles-based analysis of TMD/Py interfaces, in which the theoretically calculated intersite exchange parameters and the respective adiabatic magnon spectra reproduce the experimental trend. This study deciphers the origin of iDMI in TMD/ferromagnet heterostructures and their quantification by BLS, highlighting a possible route for the stabilization of chiral spin textures in such systems.
高效自旋电子学的发展需要自旋轨道效应和手性自旋纹理。后者需要Dzyaloshinskii-Moriya相互作用（DMI）及其与海森堡交换的相互作用。了解海森堡交换和界面DMI（iDMI）的相对强度及其与自旋轨道耦合（SOC）的标度关系，是在非磁体/铁磁体异质结构中稳定手性自旋纹理的关键。在此，利用布里渊光散射（BLS）光谱来确定与坡莫合金（Py）薄膜界面的大面积化学气相沉积单层二维（2D）过渡金属二硫属化物（TMDs）（MoS、MoSe、WS和WSe）的iDMI和海森堡交换刚度常数。对于所有四个界面，对称和反对称交换相互作用对SOC强度的依赖性几乎相同。借助基于第一性原理的TMD/Py界面分析，揭示了界面交换相互作用的起源，其中理论计算的位点间交换参数和各自的绝热磁振子谱再现了实验趋势。本研究通过BLS破译了TMD/铁磁体异质结构中iDMI的起源及其量化，突出了在此类系统中稳定手性自旋纹理的可能途径。
