Critical behaviour of the quasi-periodic quantum Ising chain
Critical behaviour of the quasi-periodic quantum Ising chain
复制标题
准周期量子伊辛链的临界行为
DOI：
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
A. Chandran
中科院分区：
文献类型：
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作者：
P. Crowley;C. Laumann;A. Chandran
相关空间调制和对称破缺的相互作用导致了介于干净和随机无序情况之间的量子临界现象。通过对准周期（QP）调制的横向场Ising链进行详细的分析和数值案例研究，我们为参考的猜想提供了证据（Crowley et al . 2018 . Phys.）。Rev. Lett. 120 175702)关于QP-Ising通用性类。在一般情况下，我们证实了对数徘徊系数w既控制宏观临界指数，也控制临界激励的能量依赖的局部化长度。然而，对于交换场耦合和横向场耦合之间的特殊相位差Δ值，QP-Ising跃迁具有不同的性质。对于Δ = 0，广义的aubry - andr<s:1>对偶性阻止了有限能量激发的局域化，尽管存在对数漂移。对于Δ这样的场和耦合是通过晶格位移联系起来的，游荡系数w消失。尽管如此，小耦合的存在导致了非平凡指数和局域激励。我们的研究结果增加了空间调制下量子伊辛跃迁的丰富种类。
The interplay of correlated spatial modulation and symmetry breaking leads to quantum critical phenomena intermediate between those of the clean and randomly disordered cases. By performing a detailed analytic and numerical case study of the quasi-periodically (QP) modulated transverse field Ising chain, we provide evidence for the conjectures of reference (Crowley et al 2018 Phys. Rev. Lett. 120 175702) regarding the QP-Ising universality class. In the generic case, we confirm that the logarithmic wandering coefficient w governs both the macroscopic critical exponents and the energy-dependent localisation length of the critical excitations. However, for special values of the phase difference Δ between the exchange and transverse field couplings, the QP-Ising transition has different properties. For Δ = 0, a generalised Aubry–André duality prevents the finite energy excitations from localising despite the presence of logarithmic wandering. For Δ such that the fields and couplings are related by a lattice shift, the wandering coefficient w vanishes. Nonetheless, the presence of small couplings leads to non-trivial exponents and localised excitations. Our results add to the rich menagerie of quantum Ising transitions in the presence of spatial modulation.
影响因子：
3.7
作者：
Szabó A
通讯作者：
Szabó A