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Two-dimensional hole gases in semiconductor quantum wells are promising platforms for spintronics and quantum computation but suffer from the lack of the $\bf{k}$-linear term in the Rashba spin-orbit coupling (SOC), which is essential for…

Mesoscale and Nanoscale Physics · Physics 2021-03-03 Jia-Xin Xiong , Shan Guan , Jun-Wei Luo , Shu-Shen Li

We present a theoretical study of the spin dynamics of a single electron confined in a quantum dot. Spin dynamics is induced by the interplay of electrical driving and the presence of a spatially disordered magnetic field, the latter being…

Mesoscale and Nanoscale Physics · Physics 2015-06-17 Gábor Széchenyi , András Pályi

We use an $sp^3d^5s^* $ tight-binding model to investigate the electronic and optical properties of realistic site-controlled (111)-oriented InGaAs/GaAs quantum dots. Special attention is paid to the impact of random alloy fluctuations on…

Materials Science · Physics 2016-09-16 R. Benchamekh , S. Schulz , E. P. O'Reilly

The spin-orbit interaction (SOI) of the two-dimensional hole gas in the inversion symmetric semiconductor Ge is studied in a strained-Ge/SiGe quantum well structure. We observed weak anti-localization (WAL) in the magnetoconductivity…

Spin qubits in germanium gate-defined quantum dots have made considerable progress within the last few years, partially due to their strong spin-orbit coupling and site-dependent $g$-tensors. While this characteristic of the $g$-factors…

Mesoscale and Nanoscale Physics · Physics 2023-11-20 John Rooney , Zhentao Luo , Lucas E. A. Stehouwer , Giordano Scappucci , Menno Veldhorst , Hong-Wen Jiang

Superconductors and semiconductors are crucial platforms in the field of quantum computing. They can be combined to hybrids, bringing together physical properties that enable the discovery of new emergent phenomena and provide novel…

We study effects of a gate-controlled Rashba spin-orbit coupling to quantum spin-Hall edge states in HgTe quantum wells. A uniform Rashba coupling can be employed in tuning the spin orientation of the edge states while preserving the…

Mesoscale and Nanoscale Physics · Physics 2011-07-21 Jukka I. Väyrynen , Teemu Ojanen

Hole spins confined in semiconductor quantum dot systems have gained considerable interest for their strong spin-orbit interactions (SOIs) and relatively weak hyperfine interactions. Here we experimentally demonstrate a tunable SOI in a…

Mesoscale and Nanoscale Physics · Physics 2022-06-09 He Liu , Ting Zhang , Ke Wang , Fei Gao , Gang Xu , Xin Zhang , Shu-Xiao Li , Gang Cao , Ting Wang , Jianjun Zhang , Xuedong Hu , Hai-Ou Li , Guo-Ping Guo

Electron spin-qubits in silicon-germanium (SiGe) heterostructures are a major candidate for the realization of scalable quantum computers. A critical challenge in strained Si/SiGe quantum wells (QWs) is the existence of two nearly…

Mesoscale and Nanoscale Physics · Physics 2025-11-20 Abel Thayil , Lasse Ermoneit , Markus Kantner

The Rashba effect in Ge/Si$_{0.15}$Ge$_{0.85}$ multiple quantum wells embedded in a p-i-n diode is studied through polarization and time-resolved photoluminescence. In addition to a sizeable redshift arising from the quantum-confined Stark…

Mesoscale and Nanoscale Physics · Physics 2022-07-25 S. Rossi , E. Talamas Simola , M. Raimondo , M. Acciarri , J. Pedrini , A. Balocchi , X. Marie , G. Isella , F. Pezzoli

We investigate the effects of homogeneous and inhomogeneous deformations and edge disorder on the conductance of gated graphene nanoribbons. Under increasing homogeneous strain the conductance of such devices initially decreases before it…

Mesoscale and Nanoscale Physics · Physics 2015-03-24 Diana A. Cosma , Marcin Mucha-Kruczynski , Henning Schomerus , Vladimir I. Fal'ko

We report direct measurements of the spin-orbit interaction induced spin-splitting in a modulation-doped GaAs two-dimensional hole system as a function of anisotropic, in-plane strain. The change in spin-subband densities reveals a…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 B. Habib , J. Shabani , E. P. De Poortere , M. Shayegan , R. Winkler

Gate geometry and bias asymmetry can be used to engineer spin dynamics in gate-defined Ge hole quantum dots by reshaping the confinement potential and driving transitions between distinct confinement regimes. In this work, we show that…

Mesoscale and Nanoscale Physics · Physics 2026-04-23 Ngoc Duong , Daryoosh Vashaee

We perform a systematic theoretical analysis of the nature and importance of alloy disorder effects on the electronic and optical properties of GaN$_{y}$As$_{1-x-y}$Bi$_{x}$ alloys and quantum wells (QWs), using large-scale atomistic…

Materials Science · Physics 2018-10-17 Muhammad Usman , Christopher A. Broderick , Eoin P. O'Reilly

Intrinsic and Rashba spin-orbit interactions in strained graphene is studied within the tight-binding (TB) approach. Dependence of Slater-Koster (SK) parameters of graphene on strain are extracted by fitting the \emph{ab initio} band…

Mesoscale and Nanoscale Physics · Physics 2019-02-08 H. Rezaei , A. Phirouznia

Kane and Mele predicted that in presence of spin-orbit interaction graphene realizes the quantum spin Hall state. However, exceptionally weak intrinsic spin-orbit splitting in graphene ($\approx 10^{-5}$ eV) inhibits experimental…

Mesoscale and Nanoscale Physics · Physics 2013-06-18 Gabriel Autès , Oleg V. Yazyev

SiGe heterostructures integrated with Si via virtual substrate (VS) growth are promising hosts for spin qubits. While VS growth targets plastic relaxation, residual cross-hatch strain inhomogeneity propagates into heterostructure…

Strong `spin'-orbit coupled one-dimensional hole gas is achievable in a Ge nanowire in the presence of a strong magnetic field. The strong magnetic field lifts the two-fold degeneracy in the hole subband dispersions, so that the effective…

Mesoscale and Nanoscale Physics · Physics 2023-02-14 Rui Li , Hang Zhang

Planar germanium quantum wells have recently been shown to host hard-gapped superconductivity. Additionally, quantum dot spin qubits in germanium are well-suited for quantum information processing, with isotopic purification to a nuclear…

In order to carefully address the interplay between substitutional disorder and spin-orbit-coupling in IV-VI alloys, we propose a novel theoretical approach that integrates the reliability of plane-wave based density-functional theory…

Materials Science · Physics 2014-07-09 Domenico Di Sante , Paolo Barone , Evgeny Plekhanov , Sergio Ciuchi , Silvia Picozzi