# Amplifying ultraweak transitions in collective systems via quantum interference

## TL;DR

This paper demonstrates how laser-induced quantum interference can enhance superradiance on ultraweak atomic transitions in a collective system, potentially enabling new high-frequency laser applications.

## Contribution

It introduces a method to amplify ultraweak transitions via quantum interference in collective atomic systems, a novel approach for controlling superradiance.

## Key findings

- Superradiance occurs on weaker transitions due to quantum interference.
- Coherent laser pumping enables amplification of ultraweak transitions.
- Potential applications in high-frequency lasing and atomic systems.

## Abstract

We investigate laser-induced quantum interference phenomena in superradiance processes and in an ensemble of initially excited $\Lambda-$type closely packed three-level emitters. The lower doublet levels are pumped with a coherent laser field. Due to constructive quantum interference effects, the superradiance occurs on a much weaker atomic transition which is not the case in the absence of the coherent driving. This result may be of visible relevance for enhancing ultraweak transitions in atomic or atomic-like systems, respectively, or for high-frequency lasing effects.