Density and pseudo-spin rotons in a bilayer of soft-core bosons
Date
2023-05-26
Editor(s)
Advisor
Supervisor
Co-Advisor
Co-Supervisor
Instructor
Source Title
Journal of Physics B: Atomic, Molecular and Optical Physics
Print ISSN
0953-4075
Electronic ISSN
1361-6455
Publisher
Institute of Physics
Volume
Volume 56
Issue
12
Pages
125001-1 - 125001-9
Language
en_US
Type
Journal Title
Journal ISSN
Volume Title
Series
Abstract
We study the dynamics of a bilayer system of bosons with repulsive soft-core Rydberg-dressed interactions within the mean-field Bogoliubov-de Gennes approximation. We find roton minima in both symmetric and asymmetric collective density modes of the symmetric bilayer. Depending on the density of bosons in each layer and the spacing between two layers, the homogeneous superfluid phase becomes unstable in either (or both) of these two channels, leading to density and pseudo-spin-density wave instabilities in the system. Breaking the symmetry between two layers, either with a finite counterflow or a density imbalance renormalizes the dispersion of collective modes and makes the system more susceptible to density-wave instability.