English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We propose a model to study the coherence and entanglement resulting from theinteraction of a finite-size atomic ensemble with degeneratecounter-propagating field modes of a high-Q ring cavity. Our approach appliesto an arbitrary number of atoms N and includes the spatial variation of thefield throughout the ensemble. We report several new interesting aspects ofcoherence and entangled behavior that emerge when the size of the atomicensemble is not taken to the thermodynamic limit of N>>1. Under suchconditions, it is found that the counter-propagating cavity modes, although inthe thermodynamic limit are mutually incoherent and exhibit no one-photoninterference, the modes can, however, be made mutually coherent and exhibitinterference after interacting with a finite-size atomic ensemble. It is alsofound that the spatial redistribution of the atoms over a finite size resultsin nonorthogonality of the collective bosonic modes. This nonorthogonalityleads to the super-bunching effect that the correlations of photons of theindividual cavity modes and of different modes are stronger than those of athermal field. However, we find that the correlations are not strong enough toviolate the Cauchy-Schwarz inequality and to produce squeezing and entanglementbetween the modes. Therefore, we investigate the spectral distributions of thelogarithmic negativity and the variances of the output fields. These functionsdetermine squeezing and entanglement properties of the output cavity fields andcan be measured by a homodyne technique. We find that the entanglement isredistributed over several components of the spectrum and the finite-sizeeffect is to concentrate the entanglement at the zero-frequency component ofthe spectrum.

Generating coherence and entanglement with a finite-size atomic ensemble in a ring cavity