Rotons and Supersolids in ultracold quantum gases of highly magnetic atoms

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• Lauriane Chomaz (IQOQI, Innsbruck)
• Thursday 05 November 2020, 13:00-14:00
• https://bham-ac-uk.zoom.us/j/9115054257? pwd=UWJqaGZpZitLUVZHQkJGby9xU2dXQT09.

If you have a question about this talk, please contact Dr Hannah Price.

Ultracold quantum gases realize an exquisite platform to study few- and many-body quantum phenomena. The achievement of quantum degeneracy in gases of atoms possessing large magnetic dipole moments has opened up new research directions where long-range anisotropic dipole-dipole interactions are competing with short-range contact interactions. Within the last few years, thanks to a fine control of this interaction competition and the subsequent occurrence of a unique stabilization mechanism based on quantum fluctuations, experiments using magnetic lanthanide atoms proved novel many-body quantum states. These include liquid-like droplets, roton excitations and, most recently, supersolids. In my talk, I will present recent results of my group in relation to the discovery and exploration of such states using gases of erbium and dysprosium in cigar- shaped traps with transverse magnetization. In the case of a regular superfluid state, the anisotropic dipole-dipole interaction may induce the existence of roton excitations along the cigar axis. The softening of these excitations under the reduction of the contact interaction strength drives a transition to density modulated states, stabilized by quantum fluctuations. The transition is relatively smooth, and, in an intermediate regime of interaction parameter, the superfluid order is maintained in the density-modulated ground-state, yielding a supersolid. In this paradoxical state, both crystal and phase excitations can come at play, yielding intriguing properties and dynamical behaviors.

This talk is part of the Theoretical Physics Seminars series.

This talk is included in these lists:

• Bham Talks
• Theoretical Physics Seminars
• What's on in Physics?
• https://bham-ac-uk.zoom.us/j/9115054257? pwd=UWJqaGZpZitLUVZHQkJGby9xU2dXQT09

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