Nonlinear two-level dynamics of quantum time crystals

S. Autti, P. J. Heikkinen, J. Nissinen, J. T. Mäkinen, G. E. Volovik, V. V. Zavyalov, V. B. Eltsov

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A time crystal is a macroscopic quantum system in periodic motion in its ground state. In our experiments, two coupled time crystals consisting of spin-wave quasiparticles (magnons) form a macroscopic two-level system. The two levels evolve in time as determined intrinsically by a nonlinear feedback, allowing us to construct spontaneous two-level dynamics. In the course of a level crossing, magnons move from the ground level to the excited level driven by the Landau-Zener effect, combined with Rabi population oscillations. We demonstrate that magnon time crystals allow access to every aspect and detail of quantum-coherent interactions in a single run of the experiment. Our work opens an outlook for the detection of surface-bound Majorana fermions in the underlying superfluid system, and invites technological exploitation of coherent magnon phenomena – potentially even at room temperature.
Original languageEnglish
Article number3090
Number of pages9
JournalNature Communications
Publication statusPublished - 2 Jun 2022


  • Bose-Einstein condensates
  • quantum fluids and solids
  • quantum mechanics
  • Magnetic properties and materials
  • helium-3
  • time crystal
  • magnon quasiparticle excitation

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