Collective excitations of two-dimensional Bose-Einstein Condensate in liquid phase with spin-orbit coupling

TL;DR

This paper investigates the collective excitations in a two-dimensional Bose-Einstein condensate with various types of spin-orbit coupling, revealing the emergence of roton modes at higher interactions.

Contribution

It provides a comprehensive analysis of how different spin-orbit couplings influence collective excitations and the appearance of roton modes in 2D Bose-Einstein condensates.

Findings

Phonon modes dominate at low interactions.

Roton modes emerge at higher interactions.

Two distinct roton modes are observed in strongly interacting systems.

Abstract

We have studied the collective excitation of Bose-Einstein condensate of short range weak interacting atoms with spin-orbit coupling (SOC) in two dimension in liquid phase. In our study, we have included Rashba, Dresselhaus SOC as well as Raman SOC. The study of Bogoliubov excitation shows that in small interaction case only phonon modes are present and for higher interactions roton modes start to appear. Energy spectra contain two roton modes in the system relatively strong interacting atomic system.