AC Josephson effect between two superfluid time crystals
Abstract
Quantum time crystals are systems characterised by spontaneously emerging periodic order in the time domain. A range of such phases has been reported. The concept has even been discussed in popular literature, and deservedly so: while the first speculation on a phase of broken time translation symmetry did not use the name "time crystal", it was later adopted from 1980's popular culture. For the physics community, however, the ultimate qualification of a new concept is its ability to provide predictions and insight. Confirming that time crystals manifest the basic dynamics of quantum mechanics is a necessary step in that direction. We study two adjacent quantum time crystals experimentally. The time crystals, realised by two magnon condensates in superfluid He-B, exchange magnons leading to opposite-phase oscillations in their populations -- AC Josephson effect -- while the defining periodic motion remains phase coherent throughout the experiment.
Cite
@article{arxiv.2003.06313,
title = {AC Josephson effect between two superfluid time crystals},
author = {Samuli Autti and Petri J. Heikkinen and Jere T. Mäkinen and Grigori E. Volovik and Vladislav V. Zavjalov and Vladimir B. Eltsov},
journal= {arXiv preprint arXiv:2003.06313},
year = {2020}
}
Comments
7 pages, 2 figures