Francesca Ferlaino and Thierry Giamarchi report in Nature Physics how “supersolid states” turn to “normal solids” and back to “supersolids” again

Francesca Ferlaino from the Institute for Experimental Physics at the University of Innsbruck and the Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, together with Thierry Giamarchi, theoretical physicist from the University of Geneva report in Nature Physics, how supersolid states react if the superfluid bath between the droplets is drained by control of the external magnetic field.

“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






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