High-dimensional Frequency-Encoded Quantum Information Processing with Passive Photonics and Time-Resolving Detection

TL;DR

This paper introduces a passive photonic approach for high-dimensional quantum information processing using frequency encoding, enabling scalable and high-fidelity operations without active control, suitable for practical implementation.

Contribution

It presents a novel passive photonic circuit design for high-dimensional frequency-encoded quantum processing, avoiding nonlinear optical processes and enabling scalable quantum operations.

Findings

Passive photonic circuits can realize arbitrary unitary transformations.

High-fidelity quantum operations are feasible with current detector technology.

A systematic design for quantum frequency combs of arbitrary size is provided.

Abstract

In this Letter, we propose a new approach to process high-dimensional quantum information encoded in a photon frequency domain. In contrast to previous approaches based on nonlinear optical processes, no active control of photon energy is required. Arbitrary unitary transformation and projection measurement can be realized with passive photonic circuits and time-resolving detection. A systematic circuit design for a quantum frequency comb with arbitrary size has been given. The criteria to verify quantum frequency correlation has been derived. By considering the practical condition of detector's finite response time, we show that high-fidelity operation can be readily realized with current device performance. This work will pave the way towards scalable and high-fidelity quantum information processing based on high-dimensional frequency encoding.