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arXiv 2401.02533math-phcond-mat.str-elhep-thmath.MP
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量子自旋链的反常对称性与 Lieb-Schultz-Mattis 定理的推广

Anomalous symmetries of quantum spin chains and a generalization of the Lieb-Schultz-Mattis theorem

Anton Kapustin, Nikita Sopenko

AI总结:

本文通过定义不依赖哈密顿量的反常指标,证明非零反常指标禁止量子自旋链中具有不变能隙基态,从而将 Lieb-Schultz-Mattis 定理推广至更一般的群对称性情形。

摘要:

对于群 $G$ 在量子自旋链上的任意保局域作用,可以定义一个取值于 $G$ 的群上同调中的反常指标。该反常指标是一个运动学量,不依赖于哈密顿量。我们证明,非零的反常指标禁止任何 $G$ 不变的哈密顿量具有 $G$ 不变的能隙基态。当 $G$ 包含平移时,Lieb-Schultz-Mattis 型定理是此结果的特例。在对称群 $G$ 为 Lie 群的情形下,我们定义了一个取值于 J.-L. Brylinski 所定义的可微群上同调中的反常指标,并证明了类似的结果。

英文摘要:

For any locality-preserving action of a group $G$ on a quantum spin chain one can define an anomaly index taking values in the group cohomology of $G$. The anomaly index is a kinematic quantity, it does not depend on the Hamiltonian. We prove that a nonzero anomaly index prohibits any $G$-invariant Hamiltonian from having $G$-invariant gapped ground states. Lieb-Schultz-Mattis-type theorems are a special case of this result when $G$ involves translations. In the case when the symmetry group $G$ is a Lie group, we define an anomaly index which takes values in the differentiable group cohomology as defined by J.-L. Brylinski and prove a similar result.

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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