# Intensified antibunching via feedback-induced quantum interference

## TL;DR

This paper demonstrates how time-delayed quantum feedback can significantly modify the statistical properties of emitted light from quantum systems, enhancing antibunching and bunching effects through quantum interference.

## Contribution

It introduces a numerical approach to control quantum light statistics using phase-selective feedback in a pumped cavity with two emitters, highlighting the role of quantum interference.

## Key findings

- Photon antibunching and bunching can be increased by orders of magnitude.
- Quantum feedback enables control over classical and nonclassical light features.
- An approximate Schrödinger picture method estimates feedback effects at low pump rates.

## Abstract

We numerically show that time delayed coherent feedback controls the statistical output characteristics of driven quantum emitters. Quantum feedback allows to enhance or suppress a wide range of classical and nonclassical features of the emitted quantum light. As exemplary quantum system, we use a pumped cavity containing two emitters. By applying phase-selective feedback, we demonstrate that photon antibunching and bunching can be increased in orders of magnitude due to intrinsically and externally controllabe quantum interferences. Our modelling is based on a fully non-Markovian quantum simulation of a structured photon continuum. We show that an approximative method in the Schr\"odinger picture allows a very good estimate for quantum feedback induced features for low pump rates.