Dark-State Polaritons for multi-component and stationary light fields

TL;DR

This paper develops a general method to identify lossless, adiabatic dark-state polaritons in complex multi-component light-matter systems, including stationary light configurations, using a generalized Morris-Shore transformation.

Contribution

It introduces a unified framework for deriving dark-state polaritons in multi-component and stationary light fields, extending previous models to more complex atomic schemes.

Findings

Existence of a single unique dark-state polariton in stationary light configurations

Derivation of a simple propagation equation for the dark-state polariton

Generalization of Morris-Shore transformation to coupled light-matter systems

Abstract

We present a general scheme to determine the loss-free adiabatic eigensolutions (dark-state polaritons) of the interaction of multiple probe laser beams with a coherently driven atomic ensemble under conditions of electromagnetically induced transparency. To this end we generalize the Morris-Shore transformation to linearized Heisenberg-Langevin equations describing the coupled light-matter system in the weak excitation limit. For the simple lambda-type coupling scheme the generalized Morris-Shore transformation reproduces the dark-state polariton solutions of slow light. Here we treat a closed-loop dual-V scheme wherein two counter-propagating control fields generate a quasi stationary pattern of two counter-propagating probe fields -- so-called stationary light. We show that contrary to previous predictions,there exists a single unique dark-state polariton; it obeys a simple propagation equation.