Generation of a maximally entangled state using collective optical pumping

TL;DR

This paper presents a new dissipative optical pumping scheme to generate a maximally entangled singlet Bell state between two ions, achieving high fidelity and robustness against noise.

Contribution

The authors introduce a novel collective optical pumping method for entangling two qubits, demonstrating its effectiveness with trapped calcium ions and analyzing its noise resilience.

Findings

Achieved 93% fidelity in entangling two ions.

Scheme is insensitive to many common noise sources.

Theoretical analysis confirms robustness and performance.

Abstract

We propose and implement a novel scheme for dissipatively pumping two qubits into a singlet Bell state. The method relies on a process of collective optical pumping to an excited level, to which all states apart from the singlet are coupled. We apply the method to deterministically entangle two trapped ${}^{40}\text{Ca}^+$ ions with a fidelity of $93(1)\%$. We theoretically analyze the performance and error susceptibility of the scheme and find it to be insensitive to a large class of experimentally relevant noise sources.