Energetically constrained co-tunneling of cold atoms

TL;DR

This paper investigates the quantum tunneling behavior of bound pairs of cold bosonic atoms in an optical lattice, revealing conditions for co-tunneling and resonant enhancement effects beyond single-atom tunneling.

Contribution

It introduces a detailed analysis of co-tunneling phenomena for bound atom pairs, including conditions for molecule-like tunneling and resonant effects, expanding understanding of multi-particle quantum tunneling.

Findings

Bound atom pairs can tunnel as a single entity under certain conditions.

Resonant enhancement significantly increases co-tunneling probability.

Atomic co-tunneling can surpass single-atom tunneling rates in specific regimes.

Abstract

We study under-barrier tunneling for a pair of energetically bound bosonic atoms in an optical lattice with a barrier. We identify conditions under which this exotic molecule tunnels as a point particle with the coordinate given by the bound pair center of mass and discuss the atomic co-tunneling beyond this regime. In particular, we quantitatively analyze resonantly enhanced co-tunneling, where two interacting atoms penetrate the barrier with higher probability than a single atom.