相干声子驱动反铁磁体中对称性选择性的非相对论自旋分裂
Symmetry-selective nonrelativistic spin splitting in antiferromagnets driven by coherent phonons
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中文总结 AI 辅助
该研究通过第一性原理计算MnPS₃，证明相干声子可动态诱导并控制反铁磁体中的非相对论自旋分裂，且能通过偏振选择性激活不同的自旋分裂相。
中文摘要 AI 辅助
反铁磁体（AFMs）中的非相对论自旋分裂（NRSS）可为超快自旋电子学实现无磁化的自旋极化。本文证明，相干声子可在共线反铁磁体中动态诱导并控制NRSS。激发Γ点红外活性声子会解除基态的自旋简并，而残留的连接亚晶格的对称性决定了诱导分裂在动量空间的形式。由于相关红外模式与正交的面内光偏振耦合，可通过驱动场的偏振选择性激活不同的自旋分裂相。针对MnPS₃的第一性原理计算表明，一种破坏所有亚晶格连接对称性的模式会诱导Δ(Γ)≠0的s波自旋分裂态，而保留亚晶格连接镜面对称性的对称不同模式则会产生Δ(Γ)=0的d波类反铁磁态。两种情况下，自旋分裂均随声子振幅线性增长，且位移反转时诱导的自旋极化也会反转。本研究确立了相干晶格驱动作为一种直接、偏振和模式选择性的途径，可在反铁磁体中动态诱导不同的NRSS相。
英文摘要
Nonrelativistic spin splitting (NRSS) in antiferromagnets (AFMs) enables magnetization-free spin polarization for ultrafast spintronics. Here, we demonstrate that coherent phonons can dynamically induce and control NRSS in collinear AFMs. Excitation of $Γ$-point infrared-active phonons lifts the spin degeneracy of the ground state, while the residual sublattice-connecting symmetries determine the momentum-space form of the induced splitting. Because the relevant infrared modes couple to orthogonal in-plane light polarizations, distinct spin-split phases can be selectively activated by the polarization of the driving field. Using first-principles calculations for MnPS$_3$, we show that a mode that breaks all sublattice-connecting symmetries induces an $s$-wave spin-split state with $Δ(Γ)\neq0$, whereas a symmetry-distinct mode that preserves a sublattice-connecting mirror symmetry generates a $d$-wave altermagnetic state with $Δ(Γ)=0$. In both cases, the spin splitting grows linearly with the phonon amplitude and reverses the induced spin polarization when the displacement is reversed. Our results establish coherent lattice driving as a direct, polarization- and mode-selective route to dynamically induce distinct NRSS phases in AFMs.
发表机构
- Lawrence Livermore National Laboratory（劳伦斯利弗莫尔国家实验室）
- Georgetown University（乔治城大学）
- Stanford University（斯坦福大学）
- SLAC National Accelerator Laboratory（SLAC国家加速器实验室）
机构由 AI 辅助整理，请以论文原文为准。
