Linear Optical Quantum Computation with Frequency-Comb Qubits and Passive Devices

TL;DR

This paper introduces a linear optical quantum computing scheme utilizing frequency-comb qubits and passive devices, offering robustness against errors and compatibility with current technology for fault-tolerance.

Contribution

It presents a novel approach encoding qubits in frequency combs and performing operations with passive optical components, eliminating the need for active switching devices.

Findings

Scheme is robust against temporal and spectral errors

Current technology nearly meets fault-tolerance requirements

Uses passive devices for quantum computation

Abstract

We propose a linear optical quantum computation scheme using time-frequency degree of freedom. In this scheme, a qubit is encoded in single-photon frequency combs, and manipulation of the qubits is performed using time-resolving detectors, beam splitters, and optical interleavers. This scheme does not require active devices such as high-speed switches and electro-optic modulators and is robust against temporal and spectral errors, which are mainly caused by the detectors' finite resolution. We show that current technologies almost meet the requirements for fault-tolerant quantum computation.