Bragg Spectroscopy of Vortex Lattices in Bose-Einstein condensates

TL;DR

This paper demonstrates a method using Bragg spectroscopy to measure and analyze the velocity field and rotation of vortex lattices in Bose-Einstein condensates, providing detailed insights into superfluid flow and quantum rotation signatures.

Contribution

It introduces a novel single-shot measurement technique combining spectral and spatial data to fully characterize vortex lattice rotation in BECs.

Findings

Successful mapping of phase gradients into diffracted atom cloud structures

Direct measurement of rotation rate and direction in vortex lattices

Observation of microscopic quantum rotation signatures

Abstract

We have measured the velocity field of a vortex lattice within a sodium Bose-Einstein condensate using Bragg scattering. The phase gradient of the macroscopic wavefunction was mapped into the spatial structure of the diffracted atom cloud, allowing for single shot measurement of the rotation parameters. A combination of spectral and spatial information yields a complete description of the superfluid flow, coarse-grained over the lattice structure, including direct and independent measurements of the rate and sense of rotation. Signatures of the microscopic quantum rotation have also been observed.