Producing superfluid circulation states using phase imprinting

TL;DR

This paper introduces a phase imprinting method using tailored light pulses to generate quantized circulation states in ring-shaped Bose-Einstein condensates, avoiding the need for angular momentum transfer.

Contribution

It presents a novel phase imprinting technique with optimized intensity patterns to produce superfluid circulation in BECs without relying on two-photon angular momentum transfer.

Findings

Successful simulation of phase imprinting with smoothed intensity profiles

Optimization of light patterns to achieve desired circulation states

Demonstration of method's robustness despite optical resolution limits

Abstract

We propose a method to prepare states of given quantized circulation in annular Bose-Einstein condensates (BEC) confined in a ring trap using the method of phase imprinting without relying on a two-photon angular momentum transfer. The desired phase profile is imprinted on the atomic wave function using a short light pulse with a tailored intensity pattern generated with a Spatial Light Modulator. We demonstrate the realization of 'helicoidal' intensity profiles suitable for this purpose. Due to the diffraction limit, the theoretical steplike intensity profile is not achievable in practice. We investigate the effect of imprinting an intensity profile smoothed by a finite optical resolution onto the annular BEC with a numerical simulation of the time-dependent Gross-Pitaevskii equation. This allows us to optimize the intensity pattern for a given target circulation to compensate for the limited resolution.