Scissors modes in generalized Gross-Pitaevskii equations

TL;DR

This paper derives a general expression for scissors mode frequencies in nonlinear systems, showing they are independent of nonlinearity form in the Thomas-Fermi regime, and validates findings with numerical simulations.

Contribution

It provides a universal analytical expression for scissors mode frequencies in nonlinear systems, confirmed by numerical simulations across different regimes.

Findings

Scissors mode frequency is independent of nonlinearity form in the Thomas-Fermi regime.

Numerical simulations confirm the transition of scissors mode frequency from non-interacting to strongly interacting regimes.

Scissors mode remains identifiable under strong quenches, aiding experimental observation.

Abstract

We investigate scissors modes in nonlinear systems with arbitrary power-law dependence of the nonlinear term. Through analytical derivation, we establish a general expression demonstrating that, in the Thomas-Fermi regime, the frequency of the scissors mode is independent of the specific form of the nonlinearity. We conclude that the scissors mode is a shear mode that does not probe the compressibility of the system, which depends on nonlinearity. To validate our findings, we perform numerical simulations of experimentally relevant Lee-Huang-Yang (LHY) systems. Our results illustrate the transition of the scissors mode frequency from the non-interacting to the strongly interacting (Thomas-Fermi) regime. Finally, we demonstrate that the scissors mode frequency remains clearly identifiable even under strong quenches, which should facilitate the experimental observation of our findings.