# Quantum correlations from dynamically modulated optical nonlinear interactions

## TL;DR

This paper explores how dynamic modulation of optical nonlinear interactions in a cavity can generate tunable, high-dimensional entangled photon states, with potential applications in quantum information processing.

## Contribution

It demonstrates the control of photon states via temporal modulation, revealing a transition from continuous to discrete entangled states and proposing new hyper-entangled state generation methods.

## Key findings

- Dynamic modulation alters nonlinear interactions and photon entanglement.
- Non-adiabatic regime creates a quantum random walk in photonic lattices.
- Adiabatic limit enables generation of hyper-entangled states.

## Abstract

We investigate optical nonlinear interactions in a dynamic environment by studying generation of photons in spontaneous parametric down conversion inside a nonlinear cavity where the optical path length is periodically modulated in time. We show that the temporal dynamics of the cavity modify the nonlinear interaction and the generated continuous variable time-frequency entangled bi-photon state evolves into a tunable discrete higher dimensional state in the non-adiabatic modulation regime where the modulation time scales are much faster than the photon lifetime. In this regime, the system mimics effects of a quantum random walk in a photonic lattice with many associated effects including localized and delocalized wavefunctions of the generated photons. We also propose generation of time-frequency hyper-entangled states in the adiabatic limit. Our analysis shows that the proposed system is promising for applications in quantum simulation and information processing in the time-frequency domain.