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arXiv · 1612.08758

Defining Time Crystals via Representation Theory

Vedika Khemani·C. W. von Keyserlingk·S. L. Sondhi
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Abstract

Time crystals are proposed states of matter which spontaneously break time translation symmetry. There is no settled definition of such states. We offer a new definition which follows the traditional recipe for Wigner symmetries and order parameters. Supplementing our definition with a few plausible assumptions we find that a) systems with time independent Hamiltonians should not exhibit TTSB while b) the recently studied $π$ spin glass/Floquet time crystal can be viewed as breaking a global internal symmetry and as breaking time translation symmetry as befits its two names.

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Vedika Khemani, C. W. von Keyserlingk, S. L. Sondhi. 2016-12-27. Defining Time Crystals via Representation Theory. https://doi.org/10.1103/physrevb.96.115127

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