Long time evolution of a spin interacting with a spin bath in arbitrary magnetic field  

作　　者：ZHAO YuKang ZHAO MeiSheng CHEN ZengBing 

机构地区：[1]Hefei National Laboratory for Physical Science at Microscale and Department of Modern Physics, University of Science and Technology of China [2]Shandong Institute of Quantum Science & Technology Co., Ltd.

出　　处：《Science China(Physics,Mechanics & Astronomy)》2014年第7期1262-1265,共4页中国科学：物理学、力学、天文学（英文版）

基　　金：supported by the National Basic Research Program of China(Grant Nos.2011CBA00300 and 2011CBA00301);the National Natural Science Foundation of China(Grant No.61033001);the Chinese Academy of Science

摘　　要：We introduce a completely different method to calculate the evolution of a spin interacting with a sufficient large spin bath,especially suitable for treating the central spin model in a quantum dot(QD).With only an approximation on the envelope of central spin,the symmetry can be exploited to reduce a huge Hilbert space which cannot be calculated with computers to many small ones which can be solved exactly.This method can be used to calculate spin-bath evolution for a spin bath containing many(say,1000)spins,without a perturbative limit such as strong magnetic field condition,and works for long-time regime with sufficient accuracy.As the spin-bath evolution can be calculated for a wide range of time and magnetic field,an optimal dynamic of spin flip-flop can be found,and more sophisticated approaches to achieve extremely high polarization of nuclear spins in a QD could be developed.We introduce a completely different method to calculate the evolution of a spin interacting with a sufficient large spin bath,especially suitable for treating the central spin model in a quantum dot（QD）.With only an approximation on the envelope of central spin,the symmetry can be exploited to reduce a huge Hilbert space which cannot be calculated with computers to many small ones which can be solved exactly.This method can be used to calculate spin-bath evolution for a spin bath containing many（say,1000）spins,without a perturbative limit such as strong magnetic field condition,and works for long-time regime with sufficient accuracy.As the spin-bath evolution can be calculated for a wide range of time and magnetic field,an optimal dynamic of spin flip-flop can be found,and more sophisticated approaches to achieve extremely high polarization of nuclear spins in a QD could be developed.

关 键 词：dipole-dipole interaction spin bath low-field regime long-time evolution numerical simulation 

分 类 号：O471.1[理学—半导体物理]