Effect of double local quenches on the Loschmidt echo and entanglement entropy of a one-dimensional quantum system. (28th April 2016)

• Record Type: Journal Article
• Authors: Rajak, Atanu; Divakaran, Uma
• Is Part Of: Journal of statistical mechanics. (2016:Apr.)
• Publication Date: 2016-04-28
• Subjects: Statistical mechanics -- Periodicals; Mechanics -- Statistical methods -- Periodicals; 530.1305
• DOI: 10.1088/1742-5468/2016/04/043107
• Languages: English
• ISSNs: 1742-5468

Abstract

Abstract: We study the effect of two simultaneous local quenches on the evolution of the Loschmidt echo (LE) and entanglement entropy (EE) of a one dimensional transverse Ising model. In this work, one of the local quenches involves the connection of two spin-1/2 chains at a certain time and the other corresponds to a sudden change in the magnitude of the transverse field at a given site in one of the spin chains. We numerically calculate the dynamics associated with the LE and the EE as a result of such double quenches, and discuss the various timescales involved in this problem using the picture of quasiparticles (QPs) generated as a result of such quenches. We perform a detailed analysis of the probability of QPs produced at the two sites and the nature of the QPs in various phases, and obtain interesting results. More specifically, we find partial reflection of these QPs at the defect center or the site of h -quench, resulting in new timescales which have never been reported before.