论文标题

旋转如何在散装卤化物钙壶中放松和开发

How Spin Relaxes and Dephases in Bulk Halide Perovskites

论文作者

Xu, Junqing, Li, Kejun, Huynh, Uyen N., Huang, Jinsong, Sundararaman, Ravishankar, Vardeny, Valy, Ping, Yuan

论文摘要

近年来,由于高度可调的旋转轨道和与晶格对称性的相互作用,近年来,卤化物钙钛矿中的旋转晶状体引起了极大的关注。自旋寿命 - 确定材料在旋转和基于旋转的量子信息应用中的适用性的关键参数 - 在卤化物钙钛矿中进行了广泛的测量,但尚未根据第一原理计算进行评估。在这里,我们利用最近开发的\ emph {ab intio}密度 - 矩阵动态框架来计算旋转放松时间($ t_ {1} $),并在Protove prototype halide perovskite perovskite $ csspbbrbrbr cons-name-cons中{$ t_ {2}^{2}^{**} $ {$ t_ {2}^{*} $)电子散射过程的耦合(SOC)和量子描述。我们还从第一原则中实施了固体的固体$ g $ factor,并在我们的动态中考虑了它,这是在外部磁场上准确捕获旋转dephasing所必需的。因此,我们将固有的自旋寿命预测为实验的上限,确定主要的自旋松弛途径,并评估对温度,外场,载体密度和杂质的依赖性。重要的是,我们发现主导载体松弛的fr {Ö} Hlich相互作用可忽略自旋松弛,这与这种相互作用的自旋相连的性质一致。我们研究了自旋轨道领域与反转不对称的效果对自旋寿命的影响,我们从计算中证明了持续的自旋螺旋可以在自旋分解很大时增强自旋寿命,但Rashba Soc无法实现。我们的理论方法可能会导致新的策略,以优化Spintronics和量子信息应用中的自旋和载体传输性能。

Spintronics in halide perovskites has drawn significant attention in recent years, due to highly tunable spin-orbit fields and intriguing interplay with lattice symmetry. Spin lifetime -- a key parameter that determines the applicability of materials for spintronics and spin-based quantum information applications -- has been extensively measured in halide perovskites, but not yet assessed from first-principles calculations. Here, we leverage our recently-developed \emph{ab initio} density-matrix dynamics framework to compute the spin relaxation time ($T_{1}$) and ensemble spin dephasing time ($T_{2}^{*}$) in a prototype halide perovskite, namely CsPbBr$_{3}$ with self-consistent spin-orbit coupling (SOC) and quantum descriptions of the electron scattering processes. We also implement the Landé $g$-factor for solids from first principles and take it into account in our dynamics, which is required to accurately capture spin dephasing at external magnetic fields. We thereby predict intrinsic spin lifetimes as an upper bound for experiments, identify the dominant spin relaxation pathways, and evaluate the dependence on temperature, external fields, carrier density,and impurities. Importantly, we find that the Fr{ö}hlich interaction that dominates carrier relaxation contributes negligibly to spin relaxation, consistent with the spin-conserving nature of this interaction. We investigated the effect of spin-orbit field with inversion asymmetry on spin lifetime, and we demonstrated from our calculation, persistent spin helix can enhance spin lifetime when the spin-split is large, but it can not be realized by Rashba SOC. Our theoretical approach may lead to new strategies to optimize spin and carrier transport properties in spintronics and quantum information applications.

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