Composite pulses for high-fidelity population inversion in optically dense, inhomogeneously broadened atomic ensembles

TL;DR

This paper introduces composite pulse sequences that enable high-fidelity population inversion in dense, inhomogeneously broadened atomic ensembles, overcoming medium distortions and offering a faster alternative to adiabatic methods.

Contribution

The authors develop composite pulses resistant to medium-induced distortions, achieving high-fidelity inversion in optically dense, inhomogeneous ensembles, bridging the gap between simple and adiabatic excitation schemes.

Findings

Achieve high-fidelity inversion at optical depths >10

Resistant to medium distortions and back-action effects

Faster than adiabatic passage schemes

Abstract

We derive composite pulse sequences that achieve high-fidelity excitation of two-state systems in an optically dense, inhomogeneously broadened ensemble. The composite pulses are resistant to distortions due to the back-action of the medium they propagate in and are able to create high-fidelity inversion to optical depths $\alpha z>10$. They function well with smooth pulse shapes used for coherent control of optical atomic transitions in quantum computation and communication. They are an intermediary solution between single $\pi$-pulse excitation schemes and adiabatic passage schemes, being far more error tolerant than the former but still considerably faster than the latter.