Transport and interaction blockade of cold bosonic atoms in a triple-well potential

TL;DR

This paper models the transport of cold bosonic atoms in a triple-well potential, revealing diamond-like structures analogous to Coulomb blockade, and demonstrates how to determine interaction energy from these features.

Contribution

It introduces a theoretical framework for analyzing atom transport in a triple-well system, highlighting the analogy with electronic Coulomb blockade and methods to extract interaction energies.

Findings

Diamond-like transport structures observed in parameter space.

Transport blockade analogous to Coulomb blockade in electronic quantum dots.

Interaction energy can be inferred from the size of the diamonds.

Abstract

We theoretically investigate the transport properties of cold bosonic atoms in a quasi one-dimensional triple-well potential that consists of two large outer wells, which act as microscopic source and drain reservoirs, and a small inner well, which represents a quantum-dot-like scattering region. Bias and gate "voltages" introduce a time-dependent tilt of the triple-well configuration, and are used to shift the energetic level of the inner well with respect to the outer ones. By means of exact diagonalization considering a total number of six atoms in the triple-well potential, we find diamond-like structures for the occurrence of single-atom transport in the parameter space spanned by the bias and gate voltages. We discuss the analogy with Coulomb blockade in electronic quantum dots, and point out how one can infer the interaction energy in the central well from the distance between the diamonds.