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arXiv 2109.04019cond-mat.str-el
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一维Lieb-Schultz-Mattis系统的非常规量子相变

Unconventional quantum phase transitions in a one-dimensional Lieb-Schultz-Mattis system

Wayne Zheng, D. N. Sheng, Yuan-Ming Lu

摘要:

研究了具有Lieb-Schultz-Mattis(LSM)型反常的一维相互作用费米子系统的量子相位和相变。具体来说,反演对称性强制任何保序间隙基态的系统是一个Kitaev链,下面的Lieb-Schultz-Mattis型定理,我们证明。或者,通过乔丹-维格纳变换,这个系统描述了一个自旋系统,其带隙的基态必须打破与费米子宇称相关的反转或伊辛对称性。利用解析方法和变分矩阵乘积态模拟得到了一个相图,并利用序参量的纠缠熵、能量方差和有限尺寸标度研究了其中量子相变的临界行为.特别是,我们观察到连续的相变之间的不同的有序相,超出了金兹伯格-朗道-威尔逊范式,在类比中的两个空间维度的量子临界点。我们证明了这类一维量子临界点可以用Tomonaga-Luttinger液体理论来描述,并提取了Luttinger参数和临界指数。我们还确定了两个有序相之间的无间隙相,这不能用U(1)Luttinger液体来描述。

英文摘要:

We study quantum phases and phase transitions in a one-dimensional interacting fermion system with a Lieb-Schultz-Mattis (LSM) type anomaly. Specifically, the inversion symmetry enforces any symmetry-preserving gapped ground state of the system to be a Kitaev chain, following a Lieb-Schultz-Mattis type theorem that we prove. Alternatively, via the Jordan-Wigner transformation, this system describes a spin system whose gapped ground states must break either the inversion or the Ising symmetry associated with fermion parity. We obtain a phase diagram using analytical methods and variational matrix product state simulations, and study the critical behaviors of the quantum phase transitions therein using entanglement entropy, energy variance and finite size scaling of order parameters. In particular, we observe continuous phase transitions between different ordered phases that are beyond the Ginzburg-Landau-Wilson paradigm, in analogy to the deconfined quantum critical points in two spatial dimensions. We show this type of 1D deconfined quantum critical point is described by the Tomonaga-Luttinger liquid theory, and extract the Luttinger parameter and critical exponents. We also identify a gapless phase between two ordered phases, which cannot be described by a U(1) Luttinger liquid.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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