Enhanced quantum state transfer via feedforward cancellation of optical phase noise

TL;DR

This paper demonstrates a feedforward method to suppress optical phase noise, significantly improving quantum state transfer efficiency in ultracold molecules, achieving near-perfect transfer rates limited only by laser intensity.

Contribution

The authors introduce an optical feedforward technique to reduce phase noise in laser systems, enhancing quantum state transfer fidelity in ultracold molecules.

Findings

Achieved 98.7% transfer efficiency in ultracold RbCs molecules.

Demonstrated suppression of optical phase noise across 114 THz.

Performed over 100 state transfers to validate the method.

Abstract

Many experimental platforms for quantum science depend on state control via laser fields. Frequently, however, the control fidelity is limited by optical phase noise. This is exacerbated in stabilized laser systems where high-frequency phase noise is an unavoidable consequence of feedback. Here we implement an optical feedforward technique to suppress laser phase noise in the STIRAP state transfer of ultracold RbCs molecules, across 114 THz, from a weakly bound Feshbach state to the rovibrational ground state. By performing over 100 state transfers on single molecules, we measure a significantly enhanced transfer efficiency of 98.7(1)% limited only by available laser intensity.