Unconditionally teleported quantum gates between remote solid-state qubit registers

TL;DR

This paper demonstrates an unconditional quantum CNOT gate between remote solid-state qubits using diamond NV centers, showcasing the potential for scalable distributed quantum computing with real-time feed-forward and entanglement.

Contribution

It introduces a method for implementing unconditional non-local quantum gates between remote solid-state qubits with real-time control and entanglement verification.

Findings

Successful demonstration of a remote CNOT gate between diamond-based qubits.

Creation of a four-partite GHZ state confirming genuine entanglement.

Implementation of non-local gates without post-selection using deterministic logic.

Abstract

Quantum networks connecting quantum processing nodes via photonic links enable distributed and modular quantum computation. In this framework, quantum gates between remote qubits can be realized using quantum teleportation protocols. The essential requirements for such non-local gates are remote entanglement, local quantum logic within each processor, and classical communication between nodes to perform operations based on measurement outcomes. Here, we demonstrate an unconditional Controlled-NOT quantum gate between remote diamond-based qubit devices. The control and target qubits are Carbon-13 nuclear spins, while NV electron spins enable local logic, readout, and remote entanglement generation. We benchmark the system by creating a Greenberger-Horne-Zeilinger state, showing genuine 4-partite entanglement shared between nodes. Using deterministic logic, single-shot readout, and real-time feed-forward, we implement non-local gates without post-selection. These results demonstrate a key capability for solid-state quantum networks, enabling exploration of distributed quantum computing and testing of complex network protocols on fully integrated systems.