Atomic Bloch-Zener Oscillations and St\"uckelberg Interferometry in Optical Lattices

TL;DR

This paper demonstrates quantum transport and band interferometry of a Bose-Einstein condensate in an optical lattice, revealing Bloch-Zener oscillations and St"uckelberg interference patterns that map the lattice's band structure.

Contribution

It introduces experimental observation of Bloch-Zener oscillations and St"uckelberg interferometry in a two-band optical lattice system, providing a new method to probe band structures.

Findings

Observation of coherent Bloch-Zener oscillations.

Demonstration of St"uckelberg interferometry in optical lattices.

Mapping of the band structure across the full Brillouin zone.

Abstract

We report on experiments investigating quantum transport and band interferometry of an atomic Bose-Einstein condensate in an optical lattice with a two-band miniband structure, realized with a Fourier-synthesized optical lattice potential. Bloch-Zener oscillations, the coherent superposition of Bloch oscillations and Landau-Zener tunneling between the two bands are observed. When the relative phase between paths in different bands is varied, an interference signal is observed, demonstrating the coherence of the dynamics in the miniband system. Measured fringe patterns of this St\"uckelberg interferometer allow to interferometrically map out the band structure of the optical lattice over the full Brillouin zone.