Tunable current circulation in triangular quantum-dot metastructures

TL;DR

This paper explores how quantum-dot triangular metastructures exhibit internal current circulation driven by quantum wave effects, with detailed analysis of correlation effects and potential for experimental testing.

Contribution

It provides an exact analysis of internal current circulation in quantum-dot triangles, revealing how correlations and interactions influence transport phenomena.

Findings

Internal current circulation occurs without magnetic fields.

Correlation strength and coupling affect circulation regimes.

Spatial interactions can enhance or suppress circulation.

Abstract

Advances in fabrication and control of quantum dots allow the realization of metastructures that may exhibit novel electrical transport phenomena. Here, we investigate the electrical current passing through one such metastructure, a system composed of quantum dots placed at the vertices of a triangle. The wave natural of quantum particles leads to internal current circulation within the metastructure in the absence of any external magnetic field. We uncover the relation between its steady-state total current and the internal circulation. By calculating the electronic correlations in quantum transport exactly, we present phase diagrams showing where different types of current circulation can be found as a function of the correlation strength and the coupling between the quantum dots. Finally, we show that the regimes of current circulation can be further enhanced or reduced depending on the local spatial distribution of the interactions, suggesting a single-particle scattering mechanism is at play even in the strongly-correlated regime. We suggest experimental realizations of actual quantum-dot metastructures where our predictions can be directly tested.