Boundary Time Crystals.

  title={Boundary Time Crystals.},
  author={Fernando Iemini and Angelo Russomanno and Jonathan Keeling and Marco Schir{\`o} and Marcello Dalmonte and Rosario Fazio},
  journal={Physical review letters},
  volume={121 3},
In this work we introduce boundary time crystals. Here continuous time-translation symmetry breaking occurs only in a macroscopic fraction of a many-body quantum system. After introducing their definition and properties, we analyze in detail a solvable model where an accurate scaling analysis can be performed. The existence of the boundary time crystals is intimately connected to the emergence of a time-periodic steady state in the thermodynamic limit of a many-body open quantum system. We also… 

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