Multiphoton interband excitations of quantum gases in driven optical lattices

TL;DR

This study observes and analyzes multiphoton interband excitations in quantum gases within shaken optical lattices, revealing high-order processes and their dependence on experimental parameters, with implications for creating new quantum phases.

Contribution

It provides the first systematic experimental and theoretical investigation of multiphoton interband excitations up to the ninth order in driven optical lattices.

Findings

Multiphoton interband excitations up to ninth order observed.

Resonance positions match ab initio calculations.

Potential to engineer novel quantum phases through tailored driving schemes.

Abstract

We report on the observation of multiphoton interband absorption processes for quantum gases in shaken light crystals. Periodic inertial forcing, induced by a spatial motion of the lattice potential, drives multiphoton interband excitations of up to the ninth order. The occurrence of such excitation features is systematically investigated with respect to the potential depth and the driving amplitude. Ab initio calculations of resonance positions as well as numerical evaluation of their strengths exhibit good agreement with experimental data. In addition our findings could make it possible to reach novel phases of quantum matter by tailoring appropriate driving schemes.