Raman laser spectroscopy of Wannier Stark states

TL;DR

This paper demonstrates the use of Raman laser spectroscopy to probe and control Wannier Stark states in a 1D lattice, enabling precise characterization of the trapping potential and atomic states.

Contribution

It introduces a method to measure couplings and transitions between Wannier Stark states using Raman lasers, providing new insights into lattice potentials and atomic control.

Findings

Resolved transitions between neighboring Wannier Stark states observed.

Couplings measured and compared to theoretical models to determine lattice depth.

Transitions to higher bands and transverse states also demonstrated.

Abstract

Raman lasers are used as a spectroscopic probe of the state of atoms confined in a shallow 1D vertical lattice. For long enough laser pulses, resolved transitions in the bottom band of the lattice between Wannier Stark states corresponding to neighboring wells are observed. Couplings between such states are measured as a function of the lattice laser intensity and compared to theoretical predictions, from which the lattice depth can be extracted. Limits to the linewidth of these transitions are investigated. Transitions to higher bands can also be induced, as well as between transverse states for tilted Raman beams. All these features allow for a precise characterization of the trapping potential and for an efficient control of the atoms external degrees of freedom.