Defining time crystals via representation theory

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  • Princeton University


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 time translation symmetry breaking 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.


Original languageEnglish
Article number115127
JournalPhysical Review B
Issue number11
Publication statusPublished - 18 Sep 2017

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