Multi-component Bose-Einstein condensation in ultracold atomic gases

S. Stringari

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.

Allan Griffin, Tetsuro Nikuni, E. Zaremba

The discovery of Bose Einstein condensation (BEC) in trapped ultracold atomic gases in 1995 has led to an explosion of theoretical and experimental research on the properties of Bose-condensed dilute gases. The first treatment of BEC at finite temperatures, this book presents a thorough account of the theory of two-component dynamics and nonequilibrium behaviour in superfluid Bose gases. It uses a simplified microscopic model to give a clear, explicit account of collective modes in both the collisionless and collision-dominated regions. Major topics such as kinetic equations, local equilibrium and two-fluid hydrodynamics are introduced at an elementary level. Explicit predictions are worked out and linked to experiments. Providing a platform for future experimental and theoretical studies on the finite temperature dynamics of trapped Bose gases, this book is ideal for researchers and graduate students in ultracold atom physics, atomic, molecular and optical physics and condensed matter physics.

Carl Wieman

Sudhir R. Jain

Enrico Compagno, Gabriele De Chiara, Dimitris G. Angelakis +1 more

A toolbox for the quantum simulation of polarons in ultracold atoms is presented. Motivated by the impressive experimental advances in the area of ultracold atomic mixtures, we theoretically study the problem of ultracold atomic impurities immersed in a Bose-Einstein condensate mixture (BEC). The coupling between impurity and BEC gives rise to the formation of polarons whose mutual interaction can be effectively tuned using an external laser driving a quasi-resonant Raman transition between the BEC components. Our scheme allows one to change the effective interactions between polarons in different sites from attractive to zero. This is achieved by simply changing the intensity and the frequency of the two lasers. Such arrangement opens new avenues for the study of strongly correlated condensed matter models in ultracold gases.