Witzel W M, Das Sarma S
Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park, Maryland 20742-4111, USA.
Phys Rev Lett. 2007 Feb 16;98(7):077601. doi: 10.1103/PhysRevLett.98.077601. Epub 2007 Feb 12.
We describe how the spin coherence time of a localized electron spin in solids, i.e., a solid state spin qubit, can be prolonged by applying designed electron spin resonance pulse sequences. In particular, the spin echo decay due to the spectral diffusion of the electron spin resonance frequency induced by the non-Markovian temporal fluctuations of the nuclear spin flip-flop dynamics can be strongly suppressed using multiple-pulse sequences akin to the Carr-Purcell-Meiboom-Gill pulse sequence in nuclear magnetic resonance. Spin coherence time can be enhanced by factors of 4-10 in GaAs quantum-dot and Si:P quantum computer architectures using composite sequences with an even number of pulses.
我们描述了如何通过应用设计好的电子自旋共振脉冲序列来延长固体中局域电子自旋（即固态自旋量子比特）的自旋相干时间。特别是，利用类似于核磁共振中的 Carr-Purcell-Meiboom-Gill 脉冲序列的多脉冲序列，可以强烈抑制由于核自旋翻转动力学的非马尔可夫时间涨落引起的电子自旋共振频率的谱扩散导致的自旋回波衰减。在 GaAs 量子点和 Si:P 量子计算机架构中，使用具有偶数个脉冲的复合序列，自旋相干时间可以提高 4 到 10 倍。
