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Charge state entropy and heat capacity of quantised states in a dopant atom quantum dot single-electron transistor
File(s)
Author(s)
Kim, Jun Hwan
Chu, Kai-Lin
Andreev, Andrei
Pyurbeeva, Eugenia
Jones, Mervyn E
Type
Journal Article
Abstract
The dependence of the entropy and heat capacity on applied drain and source bias and temperature in a few-nanometre-scale dopant atom quantum dot (QD) single- electron transistor (SET) has been investigated theoretically. In this system, the quantisation energy is comparable to the Coulomb charging energy. To make this study relevant, we choose energy scales matching experimental work on dopant atom QD SETs capable of room-temperature operation. The entropy of both a single QD, and double QDs, is investigated, where the latter provides additional information for a simple multiple QD system. Energy state diagrams are used to explain resonant tunnelling features in the Coulomb diamond plot and the Gibbs entropy S. For well-defined states within Coulomb diamonds, if spin is neglected, S tends to 0 at low temperature. In contrast, at finite drain bias, electron transport via higher energy quantised states increases their occupation probability, significantly perturbing S. Within regions of constant average current, the entropy reaches a maximum Smax = kB ln⁡M, for M ‘effective’ states. The single-electron heat capacity is extracted, using S vs. temperature plots. A Schottky anomalous heat capacity-like peak occurs, linking single-particle dynamics to macroscopic, many-particle behaviour.
Date Issued
2026-03-01
Date Acceptance
2026-03-17
Citation
Materials for Quantum Technology, 2026, 6 (1)
URI
URL
DOI
ISSN
2633-4356
Publisher
IOP Publishing
Journal / Book Title
Materials for Quantum Technology
Volume
6
Issue
1
Copyright Statement
© 2026 The Author(s). Published by IOP Publishing Ltd. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 license. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
License URL
Identifier
10.1088/2633-4356/ae5385
Subjects
dopant atom quantum dot
few particle entropy
quantum dot heat capacity
single electron transistor
Publication Status
Published
Article Number
016203
Date Publish Online
2026-03-30