Eur. Phys. J. Plus (2022) 137: 15
https://doi.org/10.1140/epjp/s13360-021-02246-6

Regular Article

Magnetic response of interacting electrons in a spatially non-uniform disordered multi-channel system: exact and mean-field results

Physics and Applied Mathematics Unit, Indian Statistical Institute, 203 Barrackpore Trunk Road, 700 108, Kolkata, India

^b santanu.maiti@isical.ac.in

Received: 29 July 2021
Accepted: 30 November 2021
Published online: 13 December 2021

Abstract

In this work, we explore magnetic response of interacting electrons in a spatially non-uniform disordered system, where impurities are introduced in one sector of the geometry keeping the other one free. The interaction among the electrons is taken in the well-known Hubbard form which leads to several anomalous features in energy spectra and flux-driven circular current, depending on the concentration of up- and down-spin electrons. For smaller systems with less number of electrons, we present exact results which always give a clear picture to understand the basic mechanisms, while for large systems having higher number of electrons mean-field results are given. The effect of disorder is very interesting. Beyond a critical disorder, completely contrasting signature is obtained compared to uniform disordered systems, and the phenomenon becomes more promising when the Hubbard interaction is included. Along with these features, we find unusual half flux-quantum periodic current at some typical cases and a suitable explanation of it is provided. Our detailed analysis may be utilized to study magnetic response of interacting electrons in other similar kind of non-uniform disordered systems.