Entropic analysis of quantum phase transitions from uniform to spatially inhomogeneous phases
Entropic analysis of quantum phase transitions from uniform to spatially inhomogeneous phases
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DOI：
10.1103/physrevlett.99.087203
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发表时间：
2007-08-24
影响因子：
8.6
通讯作者：
Noack, R. M.
中科院分区：
文献类型：
--
作者：
Legeza, O.;Solyom, J.;Noack, R. M.
我们提出了一种新的方法来研究低维费米子或自旋模型中的量子相变，从均匀相到空间非均匀相，如二聚体、三聚体或不相称相。它是基于研究有限链基态有限段的冯诺依曼熵及其相应的傅立叶谱的长度依赖性。非零波矢量的峰值是衰减相关函数的振荡行为的指示器，也提供了有关激励谱某些相关特征的重要信息；特别是，它们可以识别临界模型中软模态的波矢量。
We propose a new approach to study quantum phase transitions in low-dimensional fermionic or spin models that go from uniform to spatially inhomogeneous phases such as dimerized, trimerized, or incommensurate phases. It is based on studying the length dependence of the von Neumann entropy and its corresponding Fourier spectrum for finite segments in the ground state of finite chains. Peaks at a nonzero wave vector are indicators of oscillatory behavior in decaying correlation functions and also provide significant information about certain relevant features of the excitation spectrum; in particular, they can identify the wave vector of soft modes in critical models.