Pure bulk orbital and spin photocurrent in two-dimensional ferroelectric materials
Pure bulk orbital and spin photocurrent in two-dimensional ferroelectric materials
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二维铁电材料中的纯体轨道和自旋光电流
DOI：
10.1038/s41524-021-00531-7
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发表时间：
2020-12
影响因子：
9.7
通讯作者：
Jian Zhou
中科院分区：
文献类型：
--
作者：
Xingchi Mu;Yiming Pan;Jian Zhou
我们通过非线性响应理论阐明了无偏置光诱导的轨道和自旋电流，将中心对称破碎材料中众所周知的体光伏效应从电荷自由度推广到自旋和轨道自由度。我们使用二维的铁电材料（如GeS及其类似物）来说明这种散装轨道/自旋光伏效应，通过第一性原理计算。这些材料具有垂直镜像对称性和时间反演对称性，但缺乏反演对称性。我们发现，除了传统的光电流传播平行于镜面（线偏振光下），对称的禁戒光电流垂直于镜子实际上包含电子流，它携带角动量信息，并相反地移动。这产生具有零电荷电流的纯轨道矩电流。这种隐藏的光致纯轨道电流可以通过自旋-轨道耦合相互作用导致纯自旋电流。因此，一个四端装置可以设计成同时检测和测量光生电荷，轨道和自旋电流。所有这些电流都与极化P耦合，因此它们的幅度和方向可以通过铁电相变来控制。我们的工作提供了一个途径，推广纳米器件从光致电子学到轨道电子学和自旋电子学。
We elucidate a bias-free light-induced orbital and spin current through nonlinear response theory, which generalizes the well-known bulk photovoltaic effect in centrosymmetric broken materials from charge to the spin and orbital degrees of freedom. We use two-dimensional nonmagnetic ferroelectric materials (such as GeS and its analogs) to illustrate this bulk orbital/spin photovoltaic effect, through first-principles calculations. These materials possess a vertical mirror symmetry and time-reversal symmetry but lack of inversion symmetry. We reveal that in addition to the conventional photocurrent that propagates parallel to the mirror plane (under linearly polarized light), the symmetric forbidden photocurrent perpendicular to the mirror actually contains electrons flow, which carries angular momentum information and move oppositely. This generates a pure orbital moment current with zero electric charge current. Such hidden photo-induced pure orbital current could lead to a pure spin current via spin–orbit coupling interactions. Therefore, a four-terminal device can be designed to detect and measure photo-induced charge, orbital, and spin currents simultaneously. All these currents couple with electric polarizationP, hence their amplitude and direction can be manipulated through ferroelectric phase transition. Our work provides a route to generalizing nanoscale devices from their photo-induced electronics to orbitronics and spintronics.
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影响因子：
16.6
作者：
Xu H;Wang H;Zhou J;Li J
通讯作者：
Li J
影响因子：
8.6
作者：
H. Kontani;Takeshi Tanaka;D. Hirashima;K. Yamada;J. Inoue
通讯作者：
H. Kontani;Takeshi Tanaka;D. Hirashima;K. Yamada;J. Inoue
影响因子：
8.6
作者：
L. Tan;A. Rappe
通讯作者：
L. Tan;A. Rappe
影响因子：
4.2
作者：
Holder, Tobias;Kaplan, Daniel;Yan, Binghai
通讯作者：
Yan, Binghai
影响因子：
3.7
作者：
Kresse, G;Furthmuller, J
通讯作者：
Furthmuller, J