Radio-Frequency Hong-Ou-Mandel Interference with Conditionally Built States

TL;DR

This paper demonstrates quantum interference at radio frequencies using conditionally prepared classical states, enabling quantum effects observation without cryogenic equipment and broadening the scope of quantum protocol implementation.

Contribution

It introduces a method to simulate quantum interference in radio frequencies with classical states, bypassing the need for single-photon sources or cryogenic detectors.

Findings

Significant dips below classical correlation limit observed

High-fidelity approximation of single-photon states achieved

Tunable noise suppression demonstrated

Abstract

We report an experimental demonstration of room-temperature Hong-Ou-Mandel (HOM) interference at a radio-wave frequency of 120 MHz using conditional build-up of quantum states from classical phase-averaged coherent states. This approach enables observation of quantum effects in spectral regimes where conventional single-photon sources and detectors are unavailable or require cryogenic conditions. By constructing a high-fidelity approximation of a single-photon state with phase-averaged coherent states, we observe the normalized second-order intensity correlation dips significantly below the classical limit of 0.5. The method allows for tunable noise suppression via optimization of the state representation. Our results establish the feasibility of using conditionally prepared classical states to simulate quantum interference phenomena in the radio-frequency domain. This technique opens the door to realizing other quantum protocols, such as Bell inequality tests, in frequency ranges where standard quantum technologies are currently infeasible.