Koppens F H L, Nowack K C, Vandersypen L M K
Kavli Institute of NanoScience Delft, Delft, The Netherlands.
Phys Rev Lett. 2008 Jun 13;100(23):236802. doi: 10.1103/PhysRevLett.100.236802. Epub 2008 Jun 10.
We report a measurement of the spin-echo decay of a single electron spin confined in a semiconductor quantum dot. When we tip the spin in the transverse plane via a magnetic field burst, it dephases in 37 ns due to the Larmor precession around a random effective field from the nuclear spins in the host material. We reverse this dephasing to a large extent via a spin-echo pulse, and find a spin-echo decay time of about 0.5 micros at 70 mT. These results are in the range of theoretical predictions of the electron spin coherence time governed by the electron-nuclear dynamics.
我们报告了对限制在半导体量子点中的单个电子自旋的自旋回波衰减的测量。当我们通过磁场脉冲在横向平面中翻转自旋时，由于围绕主体材料中核自旋的随机有效场的拉莫尔进动，它在37纳秒内发生退相。我们通过自旋回波脉冲在很大程度上逆转了这种退相，并在70毫特斯拉下发现自旋回波衰减时间约为0.5微秒。这些结果在由电子-核动力学控制的电子自旋相干时间的理论预测范围内。
