Roadmap to vortex nucleation below critical rotation frequency in a dipolar Bose-Einstein condensate

TL;DR

This paper explores methods to induce vortices in dipolar Bose-Einstein condensates at lower rotation frequencies by adjusting interactions and polarization, providing new protocols for experimental vortex creation.

Contribution

It introduces three novel dynamic protocols for vortex nucleation below the critical rotation frequency in dipolar BECs, based on manipulation of interaction strength and polarization angle.

Findings

Vortex nucleation can occur below the critical frequency by tuning interactions.

The critical rotation frequency depends on dipole interaction strength and polarization.

Three protocols enable vortex formation at lower rotation speeds.

Abstract

The formation of quantized vortices in a superfluid above a certain critical trap rotation frequency serves as a hallmark signature of superfluidity. Based on the beyond mean field framework, crucial for the formation of exotic supersolid and droplet states, we investigate dynamic protocols for vortex nucleation in the superfluid and supersolid states of a dipolar Bose-Einstein condensate (BEC), at a significantly lower trap rotation frequency. We find that the critical rotation frequency of the trap varies with the dipole-dipole interaction strength and the polarization direction of the external magnetic field. Leveraging these characteristics of dipolar BECs, we demonstrate three dynamic protocols for vortex nucleation even when rotating below the critical rotation frequency viz.: (i) varying the $s$-wave scattering length, (ii) changing the polarizing angle, and (iii) successive modulation of both the scattering length and polarizing angle. These dynamic vortex seeding protocols could serve as important benchmarks for future experimental studies.