# Topological lattice using multi-frequency radiation

## TL;DR

This paper introduces a new method to generate topological lattice structures for ultra-cold atoms using multi-frequency Raman laser coupling and magnetic field gradients, resulting in non-trivial topological bands.

## Contribution

It presents a novel technique combining multi-frequency Raman coupling with magnetic gradients to create topological lattices with non-staggered flux for ultra-cold atoms.

## Key findings

- Bloch bands exhibit non-trivial topology with non-zero Chern numbers
- The method creates a rectangular lattice with uniform magnetic flux
- The technique is effective over a wide parameter range

## Abstract

We describe a novel technique for creating an artificial magnetic field for ultra-cold atoms using a periodically pulsed pair of counter propagating Raman lasers that drive transitions between a pair of internal atomic spin states: a multi-frequency coupling term. In conjunction with a magnetic field gradient, this dynamically generates a rectangular lattice with a non-staggered magnetic flux. For a wide range of parameters, the resulting Bloch bands have non-trivial topology, reminiscent of Landau levels, as quantified by their Chern numbers.