Si/SiGe Quantum Devices, Quantum Wells, and Electron-Spin Coherence

摘要: Silicon quantum devices have progressed rapidly over the past decade, driven by recent interest in spintronics and computing. Spin coherence has emerged as a leading indicator of suitable for applications. In particular, technique electron-spin resonance (ESR) proven powerful flexible probing both magnitude nature spin scattering, when compared to theoretical predictions. Here, we provide short review silicon devices, focusing on silicon/silicon-germanium wells. Our touches fabrication lithography including dots, development Schottky top gates, which recently enabled formation few-electron dots with integrated charge sensors. We discuss proposals quantum-dot computing, well spin- valley-scattering effects, may limit device performance. Recent ESR studies suggest that scattering high-mobility Si/SiGe two-dimensional electron gases be dominated D’yakonov Perel’ mechanism arising from Bychkov–Rashba spin-orbit coupling. These results rely predictions dependence time T 2 * orientation an external applied magnetic field. perform experiments series samples fabricated different methods, used obtain dots. While observe some similarities experiments, find five out six samples, angular was far larger than possible causes this discrepancy, but conclude understanding these is not yet complete.