报告题目：Dynamics of a central spin coupled to interacting spin baths
　　报告人：吴宁 北京理工大学物理学院
　　报告时间：2018年11月30日（星期五）下午15:30
　　报告地点：中国科学院武汉物理与数学研究所 磁共振楼10楼1016-17报告厅
　　报告人简介：吴宁，现任北京理工大学物理学院量子技术研究中心特别副研究员。1985年2月出生，2006年7月毕业于山东大学物理系物理学专业，2011年7月在中科院高能物理研究所理论室获理学博士学位。2011年至2016年先后在清华大学物理系、南洋理工大学材料科学与工程学院、普林斯顿大学化学系、马德里自治大学凝聚态物理系从事博士后研究工作。主要研究兴趣为量子多体系统动力学，电声耦合，強光与物质相互作用，拓扑量子态，量子输运等。在Phys. Rev. A/B、J. Chem. Phys.、J. Phys. Chem. Lett./C等学术期刊发表学术论文20余篇。
　　报告摘要：In the first part of this talk, we will discuss decoherence of a single spin-1/2 coupled to an interacting spin bath via inhomogeneous Heisenberg coupling. The bath spins are assumed to be arranged in a wheel topology with uniform nearest-neighbor XX-type intrabath coupling. We perform full quantum calculations of the real-time dynamics of the system by using results for spin-operator matrix element (SOME) in the XX spin chain. Evolution from different bath initial states, including the spin coherent state, the fully polarized state, and the antiferromagnetic state is numerically studied to reveal interesting short-time and long-time behaviors of the decoherence factor of the central spin. In the second part of the talk, I will introduce an operator approach that can be used to obtain general exact solvability requirements for the anisotropic central spin model. The method is based on a commutator scheme that has been previously applied to Richardson’s BCS model and the inhomogeneous Dicke model. The obtained conditions and the resulting Bethe ansatz equations are consistent with that in previous literature.