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

摘要

约化密度保真度（reducedensityfidelity）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—scaleentanglementreorganizationansatz）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.