Controlling subluminal to superluminal behavior of group velocity in an f-deformed Bose-Einstein condensate beyond the rotating wave approximation

TL;DR

This paper explores how to control the group velocity of light in an f-deformed Bose-Einstein condensate, enabling tunable subluminal and superluminal propagation beyond the rotating wave approximation.

Contribution

It introduces an f-deformed quantum model for BECs that accounts for counter-rotating terms and atom collisions, demonstrating enhanced control over light propagation velocities.

Findings

Group velocity can be tuned from subluminal to superluminal by adjusting deformation parameters.

Controlling deformation and atom number affects the condensate's absorptive and dispersive properties.

Beyond RWA, subluminal and superluminal behaviors are significantly enhanced.

Abstract

In this paper, we investigate tunable control of the group velocity of a weak probe field propagating through an f-deformed Bose-Einstein condensate of three-level atoms beyond the rotating wave approximation. For this purpose, we use an f- deformed generalization of an effective two-level quantum model of the three-level configuration without the rotating wave approximation in which the Gardiners phonon operators for Bose-Einstein condensate are deformed by an operator- valued function,f(n), of the particle- number operator n . Corrections produced by the counter- rotating terms appear in the first order as an intensity- dependent detuning and in the second order as an intensity- dependent atom-field coupling. We consider the collisions between the atoms as a special kind of f- deformation where the collision rate k is regarded as the deformation parameter. We demonstrate the enhanced effect of subluminal and superluminal propagation based on electromagnetically induced transparency and electromagnetically induced absorption, respectively. In particular, we find that (i) the absorptive and dispersive properties of the deformed condensate can be controlled effectively in the absence of the rotating wave approximation by changing the deformation parameter k, the total number of atoms N and the counter- rotating terms parameter, (ii) by increasing the values of k, 1/N and the counter- rotating terms parameter, the group velocity of the probe pulse changes, from subluminal to superluminal and (iii) beyond the rotating wave approximation, the subluminal and superluminal behaviors of the probe field are enhanced.