Energy gaps and interaction blockade in confined quantum systems

TL;DR

This paper explores universal properties of strongly confined quantum systems, revealing that many-body energies can be derived from single-particle eigenvalues and predicting phenomena like van-der-Waals blockade in cold atom gases.

Contribution

It demonstrates that energy gaps and blockade phenomena in confined systems can be understood through single-particle eigenvalues and exchange-correlation functional discontinuities.

Findings

Many-body energies from single-particle eigenvalues

Transport blockade linked to exchange-correlation discontinuity

Prediction of van-der-Waals blockade in cold atom gases

Abstract

Many-body effects in confined quantum systems pose a challenging problem due to the simultaneous presence of particle-particle interactions and spatial inhomogeneity. Here we investigate universal properties of strongly confined particles that turn out to be dramatically different from what is observed for electrons in atoms and molecules. We show that for a large class of harmonically confined systems, including small quantum dots and optically trapped atoms, many-body particle addition and removal energies, and energy gaps, can accurately be obtained from single-particle eigenvalues. Transport blockade phenomena are related to the derivative discontinuity of the exchange-correlation functional. This implies that they occur very generally, with Coulomb blockade being a particular realization of a more general phenomenon. In particular, we predict van-der-Waals blockade in cold atom gases in traps.