Classifying coherent peaks in nanoelectronic devices by the presence or absence of spin exchange
Abstract
Coherent peaks appearing in the differential conductance of quantum-dot single-electron transistors (QDSETs) and quantum point contact (QPC) devices are classified into two categories according to the scaling function onto which the temperature-scaled differential-conductance maxima collapse and the underlying spin dynamics. The zero-bias peaks (ZBPs) observed in QPCs and in the triplet state of the even-particle sector of QDSETs belong to the same category, whereas the ZBP in the odd-particle sector of a QDSET belongs to a different category together with all finite-bias coherent peaks observed in QPCs and in the even-particle sector of QDSETs. The spin dynamics of the former category involve spin exchange, a hallmark of Kondo dynamics, whereas those of the latter category involve only cotunneling of an up--down spin pair. Furthermore, for the former type of ZBP, the scaling temperature coincides with one-half of the full width at half maximum (FWHM), which corresponds to the Kondo temperature. In contrast, for the latter type, the scaling temperature does not coincide with the (1/2)FWHM-derived energy scale. To support these findings, the gate-voltage-dependent differential-conductance line shapes measured in the odd-particle sector of a QDSET are theoretically reproduced. The results demonstrate that the observed ZBP is a merging of two coherent side peaks generated solely by the cotunneling of up--down spin pairs.
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BibTeX
@misc{hong2026classifying,
title = {{Classifying coherent peaks in nanoelectronic devices by the presence or absence of spin exchange}},
author = {Jongbae Hong},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.00729},
eprint = {2609.00729},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.00729},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Classifying coherent peaks in nanoelectronic devices by the presence or absence of spin exchange
AU - Jongbae Hong
PY - 2026
DA - 2026/09/01
PB - arXiv
DO - 10.48550/arxiv.2609.00729
UR - https://arxiv.org/abs/2609.00729
AB - Coherent peaks appearing in the differential conductance of quantum-dot single-electron transistors (QDSETs) and quantum point contact (QPC) devices are classified into two categories according to the scaling function onto which the temperature-scaled differential-conductance maxima collapse and the underlying spin dynamics. The zero-bias peaks (ZBPs) observed in QPCs and in the triplet state of the even-particle sector of QDSETs belong to the same category, whereas the ZBP in the odd-particle sector of a QDSET belongs to a different category together with all finite-bias coherent peaks observed in QPCs and in the even-particle sector of QDSETs. The spin dynamics of the former category involve spin exchange, a hallmark of Kondo dynamics, whereas those of the latter category involve only cotunneling of an up--down spin pair. Furthermore, for the former type of ZBP, the scaling temperature coincides with one-half of the full width at half maximum (FWHM), which corresponds to the Kondo temperature. In contrast, for the latter type, the scaling temperature does not coincide with the (1/2)FWHM-derived energy scale. To support these findings, the gate-voltage-dependent differential-conductance line shapes measured in the odd-particle sector of a QDSET are theoretically reproduced. The results demonstrate that the observed ZBP is a merging of two coherent side peaks generated solely by the cotunneling of up--down spin pairs.
ER -