Multi-Orbital Quantum Phase Diffusion

TL;DR

This paper demonstrates how observing collapse and revival dynamics in a Bose-Einstein condensate within a 3D optical lattice reveals atom number statistics and multi-particle interactions, advancing quantum simulation capabilities.

Contribution

It introduces a method to directly measure multi-particle interactions generated via virtual orbital transitions in optical lattices.

Findings

Measured multi-particle interaction strengths up to six particles.

Revealed atom number statistics through collapse and revival dynamics.

Compared experimental results with theoretical predictions.

Abstract

The collapses and revivals of a coherent matter wave field of interacting particles can serve as a sensitive interferometric probe of the interactions and the number statistics of the underlying quantum field. Here we show how the ability to observe long time traces of collapse and revival dynamics of a Bose-Einstein condensate loaded into a three-dimensional (3D) optical lattice allowed us to directly reveal the atom number statistics and the presence of effective coherent multi-particle interactions in a lattice. The multi-particle interactions are generated via virtual transitions to higher lattice orbitals and can find use for simulations of effective field theories with ultracold atoms in optical lattices. We measured their absolute strengths up to the case of six-particle interactions and compare our findings with theory.