应用约化密度保真度确定自旋为1的一维量子Blume-Capel模型的基态相图  

Ground state phase diagram of the quantum spin 1 Blume-Capel model: reduced density fidelity study

作　　者：赵建辉[1] 

机构地区：[1]重庆大学科学与工程博士后流动站,重庆400030

出　　处：《物理学报》2012年第22期80-85,共6页Acta Physica Sinica

基　　金：庆市博士后科研项目(批准号:CQXM201103019)资助的课题~~

摘　　要：约化密度保真度(reduce density fidelity)可以用来描述量子多体系统的量子相变,其是两个约化密度矩阵距离的度量.本文应用MERA(multi-scale entanglement reorganization ansatz)算法,模拟自旋为1的一维量子Blume-Capel模型,并通过对约化密度保真度的计算,确定出其基态相图.单点和两点约化密度矩阵所包含的至关重要的信息的量是不同的,其会体现在约化密度保真度上.另外,本文还从局域序参量和系统能隙的角度,来探讨量子多体系统的相变.The reduced density fidelity is a measure of distance between two reduced density matrix, which can be used to characterize quantum phase transitions in quantum many-body systems. In this paper, we use the multi-scale entanglement reorganization ansatz （MERA） algorithm to simulate the spin 1 quantum Blume-Capel model and determine its ground-state phase diagram through calculat- ing the reduced density fidelity. The qualitative relevant information contained in one site reduced density matrix is different from that contained two-site reduced density matrix, which can be detected by using the reduced density fidelity. In addition, we also characterize quantum phase transitions in quantum many-body systems by using the local parameters and energy gaps.

关 键 词：量子相变 MERA 约化密度矩阵 保真度 

分 类 号：O469[理学—凝聚态物理]