Negativity of Quantumness and Non-Markovianity in a Qubit Coupled to a Thermal Ising Spin Bath System

作     者：胡征达 张逸新 张业奇 

作者机构：School of Science Jiangnan University Department of Mathematics and Physics North China Electric Power University 

出 版 物：《Communications in Theoretical Physics》 (理论物理通讯（英文版）)

年 卷 期：2014年第61卷第11期

页      面：634-640页

核心收录：

学科分类：07[理学] 0809[工学-电子科学与技术（可授工学、理学学位）] 070205[理学-凝聚态物理] 08[工学] 0704[理学-天文学] 0702[理学-物理学] 

基　　金：Supported by the National Natural Science Foundation of China under Grant Nos.11247308 and 11274274 the National Natural Science Foundation of Special Theoretical Physics under Grant No.11347196 the Natural Science Foundation of Jiangsu Province of China under Grant No.BK20130162 the Fundamental Research Funds for the Central Universities under Grant No.JUSRP11405 

主　　题：non-Markovianity negativity of quantumness critical spin bath 

摘      要：We propose a scheme to characterize the non-Markovian dynamics and quantify the non-Markovianity via the non-classicality measured by the negativity of quantumness. By considering a qubit in contact with a critical Ising spin bath and introducing an ancilla, we show that revivals of negativity of quantumness indicate the non-Markovian ***, a normalized measure of non-Markovianity based on the negativity of quantumness is introduced and the influences of bath criticality, bath temperature and bath size on the non-Markovianity are discussed. It is shown that,at the critical point, the decay of non-Markovianity versus the size of spin bath is the fastest and the non-Markovianity is exactly zero only in the thermodynamic limit. Besides, non-trivial behaviours of negativity of quantumness such as sudden change, double sudden changes and keeping constant are found for different relations between parameters of the initial state. Finally, how the non-classicality of the system is affected by a series of bang-bang pulses is also examined.