Autti, Samuli and Heikkinen, Petri and Nissinen, Jaakko and Mäkinen, Jere and Volovik, Grigori and Zavyalov, Vladislav and Eltsov, Vladimir (2022) Nonlinear two-level dynamics of quantum time crystals. Nature Communications, 13: 3090. ISSN 2041-1723
Full text not available from this repository.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.