Cavity-aided magnetic-resonance microscopy of atoms in optical lattices

TL;DR

This paper demonstrates a novel magnetic resonance imaging technique for ultracold atoms in optical lattices, achieving high spatial and number sensitivity, enabling detailed observation of atomic dynamics.

Contribution

The work introduces a cavity-aided MRI method with sub-lattice spatial resolution and minimal disturbance, advancing atomic imaging capabilities.

Findings

Achieved 120 nm spatial resolution below lattice spacing

Number sensitivity of +/-2.4 atoms per site

Observed nonequilibrium transport dynamics of atoms

Abstract

Magnetic resonance imaging (MRI) is a powerful technique for investigating the microscopic properties and dynamics of physical systems. In this work we demonstrate state-sensitive MRI of ultracold atoms in an optical lattice. Single-shot spatial resolution is 120 nm, well below the lattice spacing, and number sensitivity is +/-2.4 for 150 atoms on a single site, well below Poissonian atom-number fluctuations. We achieve this by combining high-spatial-resolution control over the atomic spin using an atom chip, together with nearly quantum-limited spin measurement, obtained by dispersively coupling the atoms to light in a high-finesse optical cavity. The MRI is minimally disruptive of the atoms' internal state, preserving the magnetisation of the gas for subsequent experiments. Using this technique, we observe the nonequilibrium transport dynamics of the atoms among individual lattice sites. We see the atom cloud initially expand ballistically, followed by the onset of interaction-inhibited transport.