A Quantum-Logic Gate between Distant Quantum-Network Modules

TL;DR

This paper demonstrates a quantum-logic gate between distant quantum modules over 60 meters, enabling remote entanglement and advancing scalable quantum network architectures.

Contribution

The first experimental realization of a non-local quantum-logic gate between remote qubit modules using photon reflection and heralding detection.

Findings

Successfully created all four Bell states remotely

Demonstrated a scalable approach for quantum networks

Extended the gate concept to multiple qubits and modules

Abstract

The big challenge in quantum computing is to realize scalable multi-qubit systems with cross-talk free addressability and efficient coupling of arbitrarily selected qubits. Quantum networks promise a solution by integrating smaller qubit modules to a larger computing cluster. Such a distributed architecture, however, requires the capability to execute quantum-logic gates between distant qubits. Here we experimentally realize such a gate over a distance of 60m. We employ an ancillary photon that we successively reflect from two remote qubit modules, followed by a heralding photon detection which triggers a final qubit rotation. We use the gate for remote entanglement creation of all four Bell states. Our non-local quantum-logic gate could be extended both to multiple qubits and many modules for a tailor-made multi-qubit computing register.