Department of Physics, Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138, USA.
Phys Rev Lett. 2009 Oct 16;103(16):160503. doi: 10.1103/PhysRevLett.103.160503. Epub 2009 Oct 14.
We report repeated single-shot measurements of the two-electron spin state in a GaAs double quantum dot. The readout allows measurement with a fidelity above 90% with a approximately 7 micros cycle time. Hyperfine-induced precession between singlet and triplet states of the two-electron system are directly observed, as nuclear Overhauser fields are quasistatic on the time scale of the measurement cycle. Repeated measurements on millisecond to second time scales reveal the evolution of the nuclear environment.
我们报告了在 GaAs 双量子点中重复进行的单次测量双电子自旋态。读出允许以高于 90%的保真度进行测量，大约每 7 微秒循环一次。通过测量循环时间内的核 Overhauser 场处于准静态，直接观察到了两电子系统中 singlet 和 triplet 态之间的超精细诱导进动。在毫秒到秒的时间尺度上进行重复测量，揭示了核环境的演化。
