Stability and excitations of solitons in 2D Bose-Einstein condensates

TL;DR

This paper investigates the stability and excitation spectrum of solitons in 2D Bose-Einstein condensates using the Kadomtsev-Petviashvili equation, revealing stable solitons and their excitation properties near the speed of sound.

Contribution

It demonstrates the stability of 2D solitons and characterizes their low-lying excitations, linking them to known 1D soliton dispersion laws.

Findings

Solitons are stable in 2D BECs near the speed of sound.

Lowest excited states follow the same dispersion as 1D gray solitons.

Discussion of these states' role in thermodynamics.

Abstract

The small oscillations of solitons in 2D Bose-Einstein condensates are investigated by solving the Kadomtsev-Petviashvili equation which is valid when the velocity of the soliton approaches the speed of sound. We show that the soliton is stable and that the lowest excited states obey the same dispersion law as the one of the stable branch of excitations of a 1D gray soliton in a 2D condensate. The role of these states in thermodynamics is discussed.