“We were able to show that without the bath the droplets quickly lose knowledge about each other and start to behave like small independent quantum systems – they dephase. The supersolid turns into a normal solid,” says Maximilian Sohmen from Francecsa Ferlaino's team. “This 'solid', however, is still soft, it can wobble and support many collective excitations, called phonons”, adds Philipp Ilzhöfer from the Innsbruck team. “This makes this state a very interesting but complex subject of study with strong connections to solid-state physics and other fields.”
Maybe surprisingly, the Innsbruck physicists were also able to reverse this dephasing process: When they replenished the background bath, the droplets renewed their communication by particle tunneling and and re-established supersolidity.
For more information see https://www.uibk.ac.at/newsroom/scrambled-supersolids.html.en
Phase coherence in out-of-equilibrium supersolid states of ultracold dipolar atoms. P. Ilzhöfer, M. Sohmen, G. Durastante, C. Politi , A. Trautmann, G. Natale, G. Morpurgo, T. Giamarchi, L. Chomaz, M. J. Mark, and F. Ferlaino. Nature Physics 2020 doi: 10.1038/s41567-020-01100-3