Amplitude and phase control of gain without inversion in a four-level atomic system using loop-transitio

TL;DR

This paper explores how amplitude and phase adjustments in a four-level atomic system can control gain without inversion, highlighting phase dependence and interference effects in loop-transition structures.

Contribution

It demonstrates phase-dependent gain without inversion in a four-level atomic system using loop transitions, a novel approach to quantum control.

Findings

Gain without inversion is achievable via amplitude control.

Gain exhibits phase dependence on the relative phase between fields.

Interference effects are key to the observed phenomena.

Abstract

Amplitude and phase control of gain without inversion is investigated in a four level loop-structure atomic system. Two features are presented. One is that gain without inversion can be obtained through the amplitude control of the applied fields. The other is that gain without inversion show a phase-dependence on the relative phase between the fields applied on the two two-photon transitions. Gain and phase-dependence originate from interference induced by such a loop-transition structure.