Interaction of quantum systems with single pulses of quantized radiation

TL;DR

This paper analyzes how quantum systems interact with single pulses of quantized radiation, revealing a Jaynes-Cummings Hamiltonian structure and providing a transformed master equation for better understanding and efficient computation.

Contribution

It introduces a transformation that clarifies the interaction dynamics and simplifies numerical solutions for quantum radiation pulses interacting with localized systems.

Findings

Identification of a Jaynes-Cummings Hamiltonian in the transformed picture

Insight into the coupling with orthogonal mode combinations

Efficient numerical solution methods for the master equation

Abstract

The interaction of a propagating pulse of quantum radiation with a localized quantum system can be described by a cascaded master equation with a distinct initially populated input and a finally populated output field mode [Phys. Rev. Lett. 123, 123604 (2019), arXiv:1902.09833v3]. By transformation to an appropriate interaction picture, we identify the usual Jaynes-Cummings Hamiltonian between the scatterer and a superposition of the initial and final mode, with a strength given by the travelling pulse mode amplitude. The transformation also identifies a coupling of the scatterer with an orthogonal combination of the two modes. The transformed master equation offers important insights into the system dynamics and it permits numerically efficient solutions.