Bound States at Semiconductor -- Mott Insulator Interfaces

TL;DR

This paper predicts the existence of quasi-particle bound states at semiconductor-Mott insulator interfaces and within heterostructures using a correlation hierarchy approach, revealing conditions for their formation.

Contribution

It introduces a theoretical framework to identify bound states at complex interfaces in correlated electron systems, highlighting the role of perturbations and spin backgrounds.

Findings

Bound states exist at semiconductor-Mott insulator interfaces.

Additional perturbations are necessary for bound states at the interface.

Bound states can form within quantum wells even without perturbations.

Abstract

Utilizing the hierarchy of correlations in the context of a Fermi-Hubbard model, we deduce the presence of quasi-particle bound states at the interface between a Mott insulator and a semiconductor, as well as within a semiconductor-Mott-semiconductor heterostructure forming a quantum well. In the case of the solitary interface, the existence of bound states necessitates the presence of an additional perturbation with a minimal strength depending on the spin background of the Mott insulator. Conversely, within the quantum well, this additional perturbation is still required to have bound states while standing-wave solutions even exist in its absence.