Non-Trivial Excited State Coherence Due to Two Uncorrelated Partially Coherent Fields

TL;DR

This paper demonstrates that uncorrelated partially coherent fields can induce long-lived excited state coherences in a closed V system, especially when the excited state splitting is small relative to the field's coherence time.

Contribution

It introduces a model showing how uncorrelated partially coherent fields can generate excited state coherences, with potential for long-lived coherence at small excited state splitting.

Findings

Uncorrelated partially coherent fields can produce excited state coherence.

Reducing excited state splitting enhances coherence lifetime.

Long-lived coherence is achievable with small excited state splitting.

Abstract

We analyze a model where a closed $V$ system is excited by two uncorrelated partially coherent fields. We use a collisionally broadened CW laser, which is a good model for an experimentally realizable partially coherent field, and show that it is possible to generate excited state coherences even if the two fields are uncorrelated. This transient coherence can be increased if splitting between the excited states is reduced relative to the radiation coherence time, $\tau_{d}$. For small excited state splitting, one can use this scheme to generate a long lived coherent response in the system.