https://doi.org/10.1140/epjp/s13360-022-02646-2
Regular Article
Spontaneous emergence of a spin state for an emitter in a time-varying medium
1
Institut Langevin, ESPCI Paris, Université PSL, CNRS, 1 rue Jussieu, 75005, Paris, France
2
Two Prime, Open Finance Group, Atlanta, USA
Received:
4
December
2021
Accepted:
24
March
2022
Published online:
7
April
2022
Time-varying media can dramatically modify the emission of embedded sources by producing time reversed waves refocusing on the source. Here, we show that such a back action can create an angular momentum by setting the source in a spontaneous spin state. We experimentally implement this coupling using self-propelled bouncing droplets sources coupled to the surface waves they emit on a parametrically excited bath. The spin state dynamics result from a self-organized interplay between the source motion and the time reversed waves. The discrete stability analysis agrees with the experimental observations. In addition, we show that these spin states provide a unique opportunity for an experimental access to parameters enabling comparison and calibration of the various existing models.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2022