Abstract

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.

Recent work has reported a realization of a time crystal in the form of the Bose-Einstein condensate of magnons in superfluid 3He. Here, the authors study the dynamics of a pair of such quantum time crystals and show that it closely resembles the evolution of a two-level system, modified by nonlinear feedback.

Details

Title
Nonlinear two-level dynamics of quantum time crystals
Author
Autti, S. 1   VIAFID ORCID Logo  ; Heikkinen, P. J. 2   VIAFID ORCID Logo  ; Nissinen, J. 3 ; Mäkinen, J. T. 3   VIAFID ORCID Logo  ; Volovik, G. E. 4 ; Zavyalov, V. V. 1 ; Eltsov, V. B. 3   VIAFID ORCID Logo 

 Aalto University, Low Temperature Laboratory, Department of Applied Physics, Aalto, Finland (GRID:grid.5373.2) (ISNI:0000000108389418); Lancaster University, Department of Physics, Lancaster, UK (GRID:grid.9835.7) (ISNI:0000 0000 8190 6402) 
 Aalto University, Low Temperature Laboratory, Department of Applied Physics, Aalto, Finland (GRID:grid.5373.2) (ISNI:0000000108389418); Royal Holloway University of London, Department of Physics, Egham, UK (GRID:grid.4970.a) (ISNI:0000 0001 2188 881X) 
 Aalto University, Low Temperature Laboratory, Department of Applied Physics, Aalto, Finland (GRID:grid.5373.2) (ISNI:0000000108389418) 
 Aalto University, Low Temperature Laboratory, Department of Applied Physics, Aalto, Finland (GRID:grid.5373.2) (ISNI:0000000108389418); L.D. Landau Institute for Theoretical Physics, Moscow, Russia (GRID:grid.436090.8) (ISNI:0000 0001 2299 7671) 
Publication year
2022
Publication date
2022
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2672488725
Copyright
© The Author(s) 2022. corrected publication 2022. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.