Perfect splitting of two-photon pulses

TL;DR

This paper demonstrates how two-photon pulses can be perfectly split and recombined in a chiral waveguide QED system, enabling precise control of photon entanglement and single-photon wave packets.

Contribution

It introduces a method to achieve perfect splitting and recombination of two-photon pulses using a cascaded system approach in waveguide QED.

Findings

Two-photon pulses can be transformed into entangled output states.

Time reversal enables perfect combination of single-photon wave packets.

The approach allows precise control over photon states in waveguide QED.

Abstract

We employ a cascaded system approach to numerically simulate the interaction of photon pulses with a two-level scatterer in a chiral waveguide QED setup. It is possible to expand any pure state of two photons as a superposition of orthogonal two-photon pulses. We show that the scattering of a two-photon pulse of suitable duration may lead to an entangled output state between predominately two equally populated two-photon states. In a complementary wave packet basis, this state is a product state of two orthogonal single photon wave packets. The time reversal of the above scattering process allows for a perfect combination of distinguishable single-photon wave packet into a single-mode pulse carrying two identical photons.