# Magnetic Field-controlled Transmission and Ultra-narrow Superradiant Lasing by Dark Atom-light Dressed States

## TL;DR

This paper demonstrates how magnetic fields can control ultra-narrow superradiant lasing and optical transmission in cold strontium-88 atoms by exploiting dark atom-light dressed states, with potential for highly precise optical clocks.

## Contribution

It provides a theoretical model explaining magnetic field-controlled superradiant lasing via dark dressed states in a three-level atom-cavity system, advancing understanding of quantum light-matter interactions.

## Key findings

- Dark atom-light dressed states enable magnetic control of optical transmission.
- Predicted superradiant lasing linewidths are tens of Hz, much narrower than cavity linewidth.
- Magnetic field mixing allows access to dark states, facilitating ultra-narrow lasing.

## Abstract

Optical lattice clock systems with ultra-cold strontium-88 atoms have been used to demonstrate superradiant lasing and magnetic field-controlled optical transmission. We explain these phenomena theoretically with a rigorous model for three-level atoms coupled to a single cavity mode. We identify a class of dark atom-light dressed states which become accessible due to mixing with bright dressed states in the presence of a magnetic field. We predict that these states, under moderate incoherent pumping, lead to lasing with a linewidth of only tens of Hz, orders of magnitude smaller than the cavity linewidth and the atomic incoherent decay and pumping rates.