A heralded quantum gate between remote quantum memories

TL;DR

This paper demonstrates a probabilistic entangling quantum gate between two distant trapped ytterbium ions, using photon interference and heralding, achieving high fidelity suitable for scalable quantum computing.

Contribution

It introduces a heralded quantum gate between remote atomic qubits mediated by photon interference, advancing scalable quantum network capabilities.

Findings

Gate fidelity of 90+-2% achieved

Successful entanglement between distant ions demonstrated

Potential for generating large entangled cluster states

Abstract

We demonstrate a probabilistic entangling quantum gate between two distant trapped ytterbium ions. The gate is implemented between the hyperfine "clock" state atomic qubits and mediated by the interference of two emitted photons carrying frequency encoded qubits. Heralded by the coincidence detection of these two photons, the gate has an average fidelity of 90+-2%. This entangling gate together with single qubit operations is sufficient to generate large entangled cluster states for scalable quantum computing.