发表机构
National Laboratory of the Rockies; STFC Daresbury Laboratory（落基山国家实验室; STFC达尔斯伯里实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文证明在偏置手性导体中，电流可打破声子螺旋度简并，使一种螺旋度优先布居，并在元素碲中通过准从头算框架验证了该效应，无需光学泵浦。
AI 中文摘要
从非磁性手性分子和晶体中产生自旋极化电子被称为手性诱导自旋选择性（CISS）。具有确定波矢 $q$ 的手性声子可以强烈增强这种效应，但在近平衡态下，两种螺旋度 $+q$ 和 $-q$ 的布居数相等：它们是时间反演伙伴，其贡献相互抵消。我们证明，在有偏置的手性导体中，电流导致一种螺旋度的声子比另一种阻尼更小。这种阻尼不对称性对电流是奇函数，在 $q\rightarrow-q$ 下为奇函数，在反转结构手性的镜像操作下不变，并且逐模式地等于电流诱导的声子坐标上的非保守贝里力。通过速率方程闭合声子动力学，这种不对称性转化为净晶格螺旋度：在任意有限偏置下，一种螺旋度被优先布居，没有阈值，随着 $V\rightarrow0$ 电流线性增长；超过阈值后，该螺旋度成为自持的相干行波。我们在元素碲中展示了这一效应，在准从头算框架内将其视为开放量子系统（电子哈密顿量、声子浴和电子-声子耦合）。电子哈密顿量由包含自旋-轨道耦合的顶点修正准粒子自洽 $GW$（QSGW）势提供；核位移通过机器学习原子间势建模，该势在 $\Gamma$-A 线上产生有限 $\pm q_z$ 的手性声子模式。核位移对电子哈密顿量的扰动通过冻结声子形变势近似。无需光学泵浦：仅偏置即可驱动电流并选择声子螺旋度；反转电流则反转选择。
英文摘要
The emergence of spin-polarized electrons from nonmagnetic chiral molecules and crystals is called Chirality-induced spin selectivity (CISS). A chiral phonon of definite wavevector $q$ can strongly enhance it, but near equilibrium the two helicities $+q$ and $-q$ are equally populated: they are time-reversal partners and their contributions cancel. We show that in a biased chiral conductor the current causes the phonon of one helicity to damp less than the other. The damping asymmetry is odd in the current, odd under $q\rightarrow-q$, invariant under a mirror that reverses the structural handedness, and equal, mode for mode, to the current-induced nonconservative Berry force on the phonon coordinate. Closing the phonon kinetics with a rate equation turns the asymmetry into a net lattice helicity: at any finite bias one helicity is preferentially populated, with no threshold, growing linearly with the current as $V\rightarrow0$; above a threshold that helicity becomes a self-sustained coherent travelling wave. We demonstrate this effect in elemental tellurium, treated as an open quantum system (electronic Hamiltonian, phonon bath, and electron-phonon coupling) within a quasi-ab initio framework. The electronic Hamiltonian is supplied by a vertex-corrected quasiparticle self-consistent $GW$ (QSGW) potential with spin-orbit coupling; nuclear displacements are modeled with a machine-learned interatomic potential, which yields chiral phonon modes at finite $\pm q_z$ on the $Γ$-A line. The perturbation to the electronic Hamiltonian from a nuclear displacement is approximated by a frozen-phonon deformation potential. No optical pump is needed: a bias alone drives the current and selects the phonon helicity; reversing the current reverses the selection.
