Jan Arlt (Aarhus University) gives a webinar on “Observation of a Lee-Huang-Yang Fluid.”

I will report on recent experiments in a mixture of Bose-Einstein condensates, where the usually dominant mean-field interactions are cancelled. In this case, the system is governed by the effect of quantum fluctuations, which are described by Lee-Huang-Yang (LHY) correction to the ground state energy. Experimentally such a LHY fluid is realized by controlling the atom numbers and interaction strengths in a 39K spin mixture confined in a spherical trap potential. We measure the monopole oscillation frequency as a function of the LHY interaction strength and find agreement with simulations of the complete experiment including the excitation procedure and inelastic losses. These results pave the way for using the non-linearity provided by the LHY term in quantum simulation experiments and for investigations beyond the LHY regime.

References:

Observation of a Lee-Huang-Yang Fluid Thomas G. Skov, Magnus G. Skou, Nils B. Jørgensen, and Jan J. Arlt, Phys. Rev. Lett. 126, 230404 (2021).

Dilute Fluid Governed by Quantum Fluctuations Nils B. Jørgensen, Georg M. Bruun, and Jan J. Arlt, Phys. Rev. Lett. 121, 173403 (2018).