Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen , 2100 Copenhagen, Denmark.
Nano Lett. 2014 Jun 11;14(6):3582-6. doi: 10.1021/nl501242b. Epub 2014 May 19.
Relaxation and dephasing of hole spins are measured in a gate-defined Ge/Si nanowire double quantum dot using a fast pulsed-gate method and dispersive readout. An inhomogeneous dephasing time T2* 0.18 μs exceeds corresponding measurements in III–V semiconductors by more than an order of magnitude, as expected for predominately nuclear-spin-free materials. Dephasing is observed to be exponential in time, indicating the presence of a broadband noise source, rather than Gaussian, previously seen in systems with nuclear-spin-dominated dephasing.
使用快速脉冲门方法和分散读出技术，在栅极定义的 Ge/Si 纳米线双量子点中测量了空穴自旋的弛豫和退相。非均匀退相时间 T2* 0.18 μs 比预期的主要无核自旋材料在 III-V 半导体中的相应测量值高出一个数量级以上。退相时间表现为指数衰减，表明存在宽带噪声源，而不是以前在核自旋主导退相系统中观察到的高斯分布。
