To understand the properties of a three-dimensional system, it is usually simpler to analyze its reduction along one spatial direction.
In the field of quantum gases, however, one-dimensional configurations display emergent properties that cannot be associated to their three-dimensional counterparts. In this talk, I will focus on two experimentally-relevant realizations of these systems: the first consists of a one-dimensional bosonic mixture of atoms coupled by a coherent drive, for which I analyze the possible solitonic solutions and discuss their collective modes. Interestingly, and differently from the three-dimensional case, these self-bound states emerge from the interplay of a repulsive mean-field energy and of the many-body attractive interaction, induced by the quantum fluctuations of the
condensate. As a second topic, I will analyze a couple of parallel quasicondensates, which are produced by splitting a single gas along the longitudinal direction (side-by-side configuration), or in the middle (head-to-tail configuration). In particular, I will derive an effective model which, for both configurations, describes the dephasing-rephasing dynamics of the relative phase between the subsystems.
References:
A. Tononi, Y. Wang, L. Salasnich, Quantum solitons in spin-orbit coupled Bose-Bose mixtures, Physical Review A, 99, 063618 (2019).
A. Tononi, F. Toigo, S. Wimberger, A. Cappellaro, and L. Salasnich, Dephasing-rephasing dynamics of one-dimensional tunneling quasicondensates, New Journal of Physics 22, 073020 (2020).
