Continuous quantum phase transitions
Continuous quantum phase transitions
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DOI：
10.1103/revmodphys.69.315
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发表时间：
1997-01-01
影响因子：
44.1
通讯作者：
Shahar, D
中科院分区：
文献类型：
--
作者：
Sondhi, SL;Girvin, SM;Shahar, D
量子系统可以在绝对零度下经历连续相变，因为进入它的哈密顿量的一些参数是变化的。这些转变是特别有趣的，在其经典的有限温度对应，其动态和静态的关键行为是密切交织在一起。通过考虑这种系统的量子统计力学的路径积分描述，获得了相当多的见解，它采取了时间作为额外维度出现的系统的经典统计力学的形式。特别是，这使得有限温度行为的标度形式的推导，这原来是由有限尺寸标度理论描述。它也自然地导致了温度依赖的退相长度的概念，它控制着量子和经典波动之间的交叉。利用这些思想，约瑟夫森结阵列和量子霍尔效应系统的实验的标度分析。
A quantum system can undergo a continuous phase transition at the absolute zero of temperature as some parameter entering its Hamiltonian is varied. These transitions are particularly interesting for, in contrast to their classical finite-temperature counterparts, their dynamic and static critical behaviors are intimately intertwined. Considerable insight is gained by considering the path-integral description of the quantum statistical mechanics of such systems, which takes the form of the classical statistical mechanics of a system in which time appears as an extra dimension. In particular, this allows the deduction of scaling forms for the finite-temperature behavior, which turns out to be described by the theory of finite-size scaling. It also leads naturally to the notion of a temperature-dependent dephasing length that governs the crossover between quantum and classical fluctuations. Using these ideas, a scaling analysis of experiments on Josephson-junction arrays and quantum-Hall-effect systems is presented.