Quantum phase transitions in random magnets

被引:2
作者
Young, AP [1 ]
机构
[1] Univ Calif Santa Cruz, Dept Phys, Santa Cruz, CA 95064 USA
基金
美国国家科学基金会;
关键词
quantum phase transitions; random magnets; critical behavior;
D O I
10.1016/S0304-8853(00)00921-5
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
This talk will discuss novel critical behavior and "Griffiths-McCoy" singularities (which occur away from criticality) near quantum phase transitions in disordered systems with discrete (Ising) symmetry. One finds that distributions of many quantities are very broad. so it is insufficient to simply take the average. After reviewing some exact results in one dimension obtained using a real space renormalization group approach, I will discuss extensions of these results obtained by a numerical method in which the spin problem is mapped on to free fermions. In this way, whole distributions can be determined with precision. The talk will then describe quantum Monte Carlo simulations which show that similar results also occur in higher dimensions, at least for d = 2. (C) 2001 Elsevier Science B.V. All rights reserved.
引用
收藏
页码:556 / 559
页数:4
相关论文
共 18 条