Two-Channel Charge-Kondo Physics in Graphene Quantum Dots

Files in This Item:
 File SizeFormat
Downloadnanomaterials-12-01513-v2.pdf979.08 kBAdobe PDF
Title: Two-Channel Charge-Kondo Physics in Graphene Quantum Dots
Authors: Minarelli, Emma L.Rigo, Jonas B.Mitchell, Andrew K.
Permanent link:
Date: 29-Apr-2022
Online since: 2022-07-04T15:32:20Z
Abstract: Nanoelectronic quantum dot devices exploiting the charge-Kondo paradigm have been established as versatile and accurate analogue quantum simulators of fundamental quantum impurity models. In particular, hybrid metal–semiconductor dots connected to two metallic leads realize the two-channel Kondo (2CK) model, in which Kondo screening of the dot charge pseudospin is frustrated. In this article, a two-channel charge-Kondo device made instead from graphene components is considered, realizing a pseudogapped version of the 2CK model. The model is solved using Wilson’s Numerical Renormalization Group method, uncovering a rich phase diagram as a function of dot–lead coupling strength, channel asymmetry, and potential scattering. The complex physics of this system is explored through its thermodynamic properties, scattering T-matrix, and experimentally measurable conductance. The strong coupling pseudogap Kondo phase is found to persist in the channel-asymmetric two-channel context, while in the channel-symmetric case, frustration results in a novel quantum phase transition. Remarkably, despite the vanishing density of states in the graphene leads at low energies, a finite linear conductance is found at zero temperature at the frustrated critical point, which is of a non-Fermi liquid type. Our results suggest that the graphene charge-Kondo platform offers a unique possibility to access multichannel pseudogap Kondo physics.
Funding Details: Enterprise Ireland
Irish Research Council
Type of material: Journal Article
Publisher: MDPI
Journal: Nanomaterials
Volume: 12
Issue: 9
Start page: 1
End page: 16
Copyright (published version): 2022 The Authors
Keywords: Kondo effectGrapheneElectronic transportQuantum dots
DOI: 10.3390/nano12091513
Language: en
Status of Item: Peer reviewed
ISSN: 2079-4991
This item is made available under a Creative Commons License:
Appears in Collections:Physics Research Collection

Show full item record

Page view(s)

Last Week
Last month
checked on Aug 14, 2022


checked on Aug 14, 2022

Google ScholarTM



If you are a publisher or author and have copyright concerns for any item, please email and the item will be withdrawn immediately. The author or person responsible for depositing the article will be contacted within one business day.