Enhanced Electron Reflectionat Mott-Insulator Interfaces

TL;DR

This paper explores an analog of the Klein paradox in a heterostructure with strongly and weakly interacting electrons, showing enhanced electron reflection linked to doublon-holon pair production.

Contribution

It introduces a new condensed matter system model that allows analytical solutions demonstrating Klein paradox-like effects.

Findings

Enhanced electron reflection observed in the heterostructure.

Doublon-holon pair production linked to Klein paradox analog.

Analytical solutions using hierarchy-of-correlations method.

Abstract

The Klein paradox describes an incoming electron being scattered at a supercritical barrier to create electron-positron pairs, a phenomenon widely discussed in textbooks. While demonstrating this phenomenon experimentally with the fundamental particles remains challenging, condensed matter analogs are more accessible to experimental realization. For spinless quasi-particles, theoretical works show an enhancement of the pair production rate, and analogs of this effect in condensed matter systems have been studied theoretically. Here, we present another condensed matter system, a heterostructure comprised of two materials with strongly and weakly interacting electrons, that allows for constructing analytical solutions using the hierarchy-of-correlations method. The results show enhanced electron reflection related with the production of doublon-holon pairs, as known from the Klein paradox.