# Generating frequency-bin qubits via spontaneous four-wave mixing in a photonic molecule

## TL;DR

This paper presents a method to generate frequency-bin photonic qubits using coupled microring resonators, enabling efficient quantum information processing with controllable and pure heralded photons.

## Contribution

It introduces a scheme for heralded frequency-bin qubit generation in a photonic molecule system with tunable coupling parameters for optimized purity and multiplexing.

## Key findings

- Coupling parameters can be optimized for nearly pure photon generation.
- Qubit state control is achieved via pump frequency amplitude.
- The scheme is independent of microring resonator mode frequency.

## Abstract

A scheme for heralded generation of frequency-bin photonic qubits via spontaneous four-wave mixing in a system of coupled microring resonators (photonic molecule) is developed so that the qubit state is fully controlled by the frequency amplitude of the pump field. It is shown that coupling parameters of the photonic molecule can be optimized to provide generation of nearly pure heralded photons. The heralded qubit state does not depend on the microring resonator mode frequency, thereby allowing to take advantage of frequency multiplexing for improving efficiency of quantum information processing.