Deterministic Quantum Network for Distributed Entanglement and Quantum Computation

TL;DR

This paper introduces a deterministic quantum network protocol that enables high-fidelity multi-qubit entangling gates across distributed quantum nodes, facilitating scalable quantum computing.

Contribution

It presents a novel interaction protocol for deterministic multi-qubit entangling gates in scalable quantum networks, improving fidelity over traditional methods.

Findings

High-fidelity multi-qubit controlled phase gates achieved

Protocol applicable to various quantum architectures

Enhanced efficiency for distributed quantum computing

Abstract

We propose a simple interaction protocol to be implemented on a scalable quantum network, in which the quantum nodes consist of qubit systems confined in cavities. The nodes are deterministically coupled by transmission and reflection of a single photon, which is disentangled from the qubits at the end of the coupling operation. This single photon can generate an entangling controlled phase (C-PHASE) gate between any selected number of qubits in the network. Our multi-qubit gate reaches a much higher fidelity compared to schemes concatenating one-qubit and two-qubit gates; thus it forms an efficient basis for universal quantum computing distributed over multiple processor units. In our analysis we consider atomic qubits coupled to optical photons, while the scheme can be readily generalized to other architectures, such as superconducting qubit nodes coupled by microwave photons.