Ultracold Bose gases - from the Gross-Pitaevskii to the fractional quantum Hall regime

Louis Jacome, Jianshi Zhao, Nathan Gemelke

Louis Jacome, Jianshi Zhao, Nathan Gemelke

Xibo Zhang, Wei Qi, Ming-Cheng Liang

B. Paredes, P. Zoller, J. I. Cirac

S. Boucherf, Mohammed Ahmed Ammar

The emergence of macroscopic quantum coherence appears through Bose–Einstein condensation (BEC), which was first seen in superfluid helium and later achieved in ultracold atomic gases as a weakly interacting quantum fluid. This article aims to provide a study of the rotational properties of a two-component ultracold bosonic mixture with homogeneous and inhomogeneous interactions in the fractional quantum Hall (FQH) regime, where strong effective magnetic fields or rapid rotation drive the system into a strongly correlated quantum fluid state. Ultracold atomic gases offer a versatile experimental platform to realize and test the predictions of the composite fermion approach, bridging condensed matter physics with atomic physics through the unifying concept of weakly interacting quantum fluids emerging from strong correlations. A quantum interference-based atom laser in a two-component BEC is scientifically original and technologically promising, following recent advances in multi-species condensates. In this article, we explore the possibility of realizing an atom laser from ultracold binary atomic gases via their rotational properties in the FQH regime, where the controlled emission of quasiholes or coherent matter waves from the correlated state may provide a route toward an atom-laser scheme based on strongly correlated FQH states.

Morris Brooks

We present a novel approach to the Bogoliubov theory of dilute Bose gases, allowing for an elementary derivation of the celebrated Lee-Huang-Yang formula in the Gross-Pitaevskii regime. Furthermore, we identify the low lying excitation spectrum beyond the Gross-Pitaevskii scaling, extending a recent result (Brennecke et al. in Rev Math Phys 34, 2022) to significantly more singular scaling regimes. Finally, we provide an upper bound on the ground state energy in the Gross-Pitaevskii regime that captures the correct expected order of magnitude beyond the Lee-Huang-Yang formula.