Hyperfine and Optical Barium Ion Qubits

TL;DR

This paper demonstrates advanced control and measurement techniques for two types of barium ion qubits, including an optical qubit at 1.76 μm and a hyperfine qubit at 8 GHz, achieving high fidelity operations.

Contribution

It introduces methods for state preparation, rotation, and readout of both optical and hyperfine barium ion qubits, with improved fidelity and versatility.

Findings

Successful implementation of optical qubit at 1.76 μm

High fidelity readout of hyperfine qubit at 8 GHz

Techniques transferable to other ion-based quantum systems

Abstract

State preparation, qubit rotation, and high fidelity readout are demonstrated for two separate \baseven qubit types. First, an optical qubit on the narrow 6S$_{1/2}$ to 5D$_{5/2}$ transition at 1.76 $\mu$m is implemented. Then, leveraging the techniques developed there for readout, a ground state hyperfine qubit using the magnetically insensitive transition at 8 GHz is accomplished.