Institute of Theoretical Physics

Chinese Academy of Sciences

State Key Laboratory of Theoretical Physics

Seminar

Title

题目

Self-sustained Clusters in Spin Models and their Link to Ergodicity Breaking

Speaker

报告人

Dr. Bill Chi-Ho Yeung

Affiliation

所在单位

Department of Science and Environmental Studies, The Hong Kong Institute of Education, Hong Kong, China

Date

日期

July 10, Friday, 14:00--15:00

Venue

地点

理论所新楼6420教室

Abstract

摘要

We study the entropy of self-sustained spin clusters in disordered systems, where in-cluster local fields are dominated by cluster spins and are therefore difficult to destabilize. Self-sustained spin clusters are shown to be analytically linked to ergodicity breaking in fully connected Ising and Sherrington-Kirkpatrick (SK) models, relating the less understood spin space characteristics to the well understood macroscopic state space properties. This correspondence is established through the absence of clusters in the paramagnetic phase, the presence of one dominant cluster in the Ising ferromagnet, and the formation of a non-trivial profile of self-sustained clusters in the SK spin glass. Yet unobserved phenomena are also revealed such as a first order phase transition in cluster sizes in the SK ferromagnet. The analysis was carried out under the replica symmetric and one-step replica symmetry breaking ansatz and could be adapted to investigate other spin models.

Contact Personn

所内合作者