Resonant tunneling in graphene pseudomagnetic quantum dots

TL;DR

This paper investigates how strain-induced pseudomagnetic fields in graphene quantum dots influence resonant tunneling, revealing valley filtering and controllable transport properties in strained graphene nanostructures.

Contribution

It provides a detailed analysis of electronic transport in strained graphene quantum dots, highlighting the role of pseudomagnetic fields and external fields in controlling tunneling and valley filtering.

Findings

Strain induces pseudomagnetic fields that enable Landau level-assisted tunneling.

External fields break valley degeneracy, allowing valley-specific filtering.

Asymmetric strain can control the exit channel in Y-junctions.

Abstract

Realistic relaxed configurations of triaxially strained graphene quantum dots are obtained from unbiased atomistic mechanical simulations. The local electronic structure and quantum transport characteristics of y-junctions based on such dots are studied, revealing that the quasi-uniform pseudomagnetic field induced by strain restricts transport to Landau level- and edge state-assisted resonant tunneling. Valley degeneracy is broken in the presence of an external field, allowing the selective filtering of the valley and chirality of the states assisting in the resonant tunneling. Asymmetric strain conditions can be explored to select the exit channel of the y-junction.