Design Methodologies for Integrated Quantum Frequency Processors

TL;DR

This paper presents a new integrated photonics design methodology for quantum frequency processors using microring resonators and phase modulators, enabling scalable, high-fidelity quantum gates with compact, low-loss components.

Contribution

It introduces a general, extendable model for integrated quantum frequency processors that improves scalability and performance over traditional fiber-optic implementations.

Findings

High fidelity for single and parallel frequency-bin Hadamard gates

Potential for tight frequency spacings in integrated platforms

Model applicable to various material platforms

Abstract

Frequency-encoded quantum information offers intriguing opportunities for quantum communications and networking, with the quantum frequency processor paradigm -- based on electro-optic phase modulators and Fourier-transform pulse shapers -- providing a path for scalable construction of quantum gates. Yet all experimental demonstrations to date have relied on discrete fiber-optic components that occupy significant physical space and impart appreciable loss. In this article, we introduce a model for the design of quantum frequency processors comprising microring resonator-based pulse shapers and integrated phase modulators. We estimate the performance of single and parallel frequency-bin Hadamard gates, finding high fidelity values that extend to frequency bins with relatively wide bandwidths. By incorporating multi-order filter designs as well, we explore the limits of tight frequency spacings, a regime extremely difficult to obtain in bulk optics. Overall, our model is general, simple to use, and extendable to other material platforms, providing a much-needed design tool for future frequency processors in integrated photonics.