Transverse rectification in density-modulated two-dimensional electron gases

Controlled charge and spin current rectifications in a spin polarized device

Quasicrystals have been the subject of intense research in the discipline of condensed matter physics due to their non-trivial characteristic features. In the present work we put forward a new prescription to realize both charge and spin current rectifications considering a one-dimensional quasicrystal whose site energies and/or nearest-neighbor hopping (NNH) integrals are modulated in the form of well known Aubry-André or Harper (AAH) model, a classic example of an aperiodic system. Each site of the chain contains a finite magnetic moment which is responsible for spin separation, and, in pres…

Photoinduced electronic and spin properties of two-dimensional electron gases with Rashba spin-orbit coupling under perpendicular magnetic fields

We theoretically investigate photoinduced phenomena induced by time-periodic driving fields in two-dimensional electron gases under perpendicular magnetic fields with Rashba spin-orbit coupling. Using perturbation theory, we provide analytical results for the Floquet-Landau energy spectrum appearing due to THz radiation. By employing the resulting photo-modulated states, we compute the dynamical evolution of the spin polarization function for an initially prepared coherent state. We find that the interplay of the magnetic field, Rashba spin-orbit interaction and THz radiation can lead to inver…

单向横向超晶格中Shubnikov-de Haas振荡的调制

Modulation of the Shubnikov-de Haas Oscillation in Unidirectional Lateral Superlattices

本文详细分析了二维电子气在弱单向周期势调制作用下的Shubnikov-de Haas振荡的振幅和相位。在低磁场的最大带宽条件下，振幅被抑制，伴随着相位的反转。随着磁场的增加，抑制逐渐被增强所取代。抑制和增强分别归因于调制电位对电导率的碰撞和扩散贡献，前者（后者）在低（高）磁场下占主导地位。考虑到这两种类型的贡献的理论计算显示半定量协议与实验痕迹。

光诱导下 KTaO3 (111) 界面二维电子气中非线性霍尔效应的巨增强

Light-Induced Giant Enhancement of the Nonlinear Hall Effect in Two-Dimensional Electron Gases at KTaO3 (111) Interfaces

本文报道了在 CaZrO3/KTaO3 (111) 界面二维电子气中通过光照实现非线性霍尔效应近五个数量级的巨增强及符号反转，揭示斜散射主导机制和 Berry 曲率随能带填充变化的物理起源，为光控非线性电子器件开辟新途径。

Quantum systems under frequency modulation

We review the physical phenomena that arise when quantum mechanical energy levels are modulated in time. The dynamics resulting from changes in the transition frequency is a problem studied since the early days of quantum mechanics. It has been of constant interest both experimentally and theoretically since, with the simple two-state model providing an inexhaustible source of novel concepts. When the transition frequency of a quantum system is modulated, several phenomena can be observed, such as Landau-Zener-Stückelberg-Majorana interference, motional averaging and narrowing, and the formati…

Fibonacci横向超晶格可伸缩性振荡的Fourier分析

Fourier analyses of commensurability oscillations in Fibonacci lateral superlattices

磁输运测量已经在斐波那契横向超晶格（FLSL）上进行了--二维电子气受到以斐波那契序列排列的弱电势调制，LSLLSLS...，L/S=tau（黄金比例）。观察到复杂的可伸缩性振荡（CO），这可以被解释为一系列CO的叠加，每个CO产生的正弦调制代表的特征长度尺度的自相似世代之一的斐波那契序列。通过数值傅立叶带通滤波器，可以从磁阻迹线中分离出单个CO分量。从这样提取的单分量CO的振幅的分析，可以评估电势调制中的对应傅立叶分量的幅度。通过检查在磁阻迹线中观察到的所有傅立叶内容，可以重建由电子看到的调制电势的轮廓，其中关于不同分量之间的相位的相互关系存在一些不确定性。