Ground state overlap and quantum phase transitions
Ground state overlap and quantum phase transitions
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DOI：
10.1103/physreve.74.031123
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发表时间：
2006-09-01
影响因子：
2.4
通讯作者：
Paunkovic, Nikola
中科院分区：
文献类型：
--
作者：
Zanardi, Paolo;Paunkovic, Nikola
对于两个不同的外部参数值，我们用两个基态之间的重叠函数来刻画量子相变。在Dicke和XY模型的例子中，我们证明了系统的临界区域是由重叠的极值点和与其密切相关的函数来标记的。此外，我们还讨论了这种方法与Anderson正交性突变以及临界系统Loschmidt回波的动力学研究之间的联系。
We present a characterization of quantum phase transitions in terms of the the overlap function between two ground states obtained for two different values of external parameters. On the examples of the Dicke and XY models, we show that the regions of criticality of a system are marked by the extremal points of the overlap and functions closely related to it. Further, we discuss the connections between this approach and the Anderson orthogonality catastrophe as well as with the dynamical study of the Loschmidt echo for critical systems.