Universal gate-set for trapped-ion qubits using a narrow linewidth diode laser

TL;DR

This paper demonstrates a high-fidelity universal gate-set for trapped-ion qubits using a narrow linewidth diode laser, enabling precise quantum operations with improved stability and spectral filtering.

Contribution

It introduces a novel implementation of quantum gates on optical qubits with a stabilized diode laser and master-slave configuration, enhancing fidelity and control.

Findings

High fidelity single qubit gates achieved

Two-qubit Mølmer-Sørensen entangling gate demonstrated

Laser spectrum characterized with modified Ramsey sequence

Abstract

We report on the implementation of a high fidelity universal gate-set on optical qubits based on trapped $^{88}$Sr$^+$ ions for the purpose of quantum information processing. All coherent operations were performed using a narrow linewidth diode laser. We employed a master-slave configuration for the laser, where an ultra low expansion glass (ULE) Fabry-Perot cavity is used as a stable reference as well as a spectral filter. We characterized the laser spectrum using the ions with a modified Ramsey sequence which eliminated the affect of the magnetic field noise. We demonstrated high fidelity single qubit gates with individual addressing, based on inhomogeneous micromotion, on a two-ion chain as well as the M{\o}lmer-S{\o}rensen two-qubit entangling gate.