Stern-Gerlach detection of neutral atom qubits in a state dependent optical lattice

TL;DR

This paper presents a high-fidelity, non-destructive method for measuring the quantum state of ~160 Cesium atom qubits in a 3D optical lattice using a Stern-Gerlach-like technique, enabling re-initialization and replacement of atoms.

Contribution

It introduces a novel Stern-Gerlach-based detection scheme for neutral atom qubits that achieves near-perfect fidelity without atom loss, allowing for re-initialization of the quantum register.

Findings

Measurement fidelity of 0.9994 achieved.

Detection scheme is independent of the number of qubits.

Re-initialization and atom replacement demonstrated.

Abstract

We demonstrate qubit state measurement for ~160 Cesium atoms in a 3D optical lattice based on coherent spatial splitting of the atoms' wavefunctions. The measurement fidelity is 0.9994, essentially independent of the number of qubits measured. The detection scheme is reminiscent of the Stern-Gerlach experiment, but carried out in light traps. The measurement causes no loss, which allows us to demonstrate re-initialization of the 3D qubit array after state measurement, including the replacement of an atom lost to a background gas collision.