SAMOP 2021 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 14: Ultracold atoms, ions, and BEC II / Ultracold plasmas and Rydberg systems (joint session A/Q)
Q 14.4: Invited Talk
Thursday, September 23, 2021, 12:15–12:45, H1
Fate of the Amplitude Mode in a Trapped Supersolid — •Mingyang Guo1, Jens Hertkorn1, Fabian Böttcher1, Jan-Niklas Schmidt1, Tim Langen1, Hans Peter Büchler2, and Tilman Pfau1 — 15. Physikalisches Institut and Center for Integrated Quantum Science and Technology IQST, Universität Stuttgart — 2Institute for Theoretical Physics III and Center for Integrated Quantum Science and Technology IQST, Universität Stuttgart
Bose-Einstein condensates (BECs) with strong magnetic dipolar interactions have an excitation spectrum that can feature a minimum known as roton minimum. In a certain interaction parameter range, the roton can induce an instability to the ground state leading to the formation of quantum droplets purely stabilized by quantum fluctuations. These droplets have been shown to realize a counter-intuitive phase of matter called supersolid, which combines the frictionless flow of a superfluid with the crystalline order of a solid.
We theoretically investigate the spectrum of elementary excitations of a trapped dipolar quantum gas across the BEC-supersolid phase transition. The energetically low-lying excitations and the relation between the spectrum of the BEC and the supersolid reveal the existence of distinct Higgs amplitude and Nambu-Goldstone modes that emerge from the softening roton modes at the phase transition point [1].
[1] J. Hertkorn et al., Phys. Rev. Lett. 123, 193002 (2019)