Quantum photonic frequency processor on thin-film lithium niobate

TL;DR

This paper demonstrates a scalable, integrated quantum photonic frequency processor on thin-film lithium niobate, enabling precise control and universal quantum logic operations on frequency-encoded photon states.

Contribution

It introduces a fully integrated, scalable architecture for frequency-encoded quantum information processing using thin-film lithium niobate, including universal quantum gates.

Findings

Realized a universal set of frequency-encoded quantum logic gates

Achieved high fidelity characterization of frequency-bin entangled states

Demonstrated coherent and programmable control of photon frequency

Abstract

The rapid development of photonic quantum information processing necessitates precise and programmable control over optical frequency, a capability critical not only for achieving photon indistinguishability but also for exploiting a virtually unbounded frequency dimension. However, efficient and scalable processing of frequency-encoded photon states remains challenging, primarily due to the limited nonlinear optical interaction in most photonic materials. Here, by harnessing the high-performance thin-film lithium niobate electro-optic (EO) platform, we demonstrate an integrated quantum photonic frequency processor that enables coherent and programmable control of photon frequency with high precision. We establish a scalable architecture for frequency-encoded quantum information processing. Using a fully integrated photonic chip, we realize a universal set of frequency-encoded quantum logic gates, including arbitrary single-qubit rotation gates and the two-qubit controlled-phase gate. Furthermore, we demonstrate its application in high fidelity characterization of frequency-bin entangled states. Our work reveals the unprecedented potential of utilizing the frequency degree of freedom in integrated quantum photonic systems.