Programmable Quantum Linear Interference with Pulse Shaping of Quantum Light

TL;DR

This paper introduces a new method for programmable quantum interference using pulse shaping of quantum light, enabling scalable quantum computing without nonlinear effects or spatial beam splitters.

Contribution

It presents a novel frequency-domain interference technique that allows programmable quantum operations through spectral mode control and independent frequency band measurements.

Findings

Demonstrated frequency-domain Hong-Ou-Mandel interference experimentally.

Achieved programmable quantum interference by spectral mode and measurement basis control.

Proposed a scalable approach for photonic quantum computing without nonlinearities.

Abstract

In this paper, we propose a novel method for interfering frequency-multiplexed photonic quantum states without the use of optical nonlinear effects, and experimentally demonstrate this technique via frequency-domain Hong-Ou-Mandel (HOM) interference. By cascading the generation of quantum states onto arbitrary orthogonal modes, we can induce interference across any desired frequency mode. Following the generation of quantum states onto the frequency modes, performing measurements in independent frequency bands enables the realisation of a frequency-domain linear optical circuit analogous to linear interference in the spatial domain. We successfully demonstrated programmable quantum interference by controlling the spectral mode functions and measurement bases. Our method offers a new approach to harness the full potential of light's temporal-frequency degrees of freedom, providing a path towards scalable and programmable photonic quantum computing architectures without the need for optical nonlinearities or spatial-mode beam splitters.