Singlet-Triplet Kondo Effect in Blatter Radical Molecular Junctions: Zero-bias Anomalies and Magnetoresistance

Fuente: arXiv
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Main Authors: Mitra, Gautam, Zheng, Jueting, Schaefer, Karen, Deffner, Michael, Low, Jonathan Z., Campos, Luis M., Herrmann, Carmen, Costi, Theo A., Scheer, Elke
Format: Preprint
Published: 2024
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author Mitra, Gautam
Zheng, Jueting
Schaefer, Karen
Deffner, Michael
Low, Jonathan Z.
Campos, Luis M.
Herrmann, Carmen
Costi, Theo A.
Scheer, Elke
author_facet Mitra, Gautam
Zheng, Jueting
Schaefer, Karen
Deffner, Michael
Low, Jonathan Z.
Campos, Luis M.
Herrmann, Carmen
Costi, Theo A.
Scheer, Elke
contents The Blatter radical has been suggested as a building block in future molecular spintronic devices due to its radical character and expected long-spin lifetime. However, whether and how the radical character manifests itself in the charge transport and magnetotransport properties seems to depend on the environment or has not yet been studied. Here, we investigate single-molecule junctions of the Blatter radical molecule in a mechanically controlled break junction device at low temperature. Differential conductance spectroscopy on individual junctions shows two types of zero-bias anomalies attributed to Kondo resonances revealing the ability to retain the open-shell nature of the radical molecule in a two-terminal device. Additionally, a high negative magnetoresistance is also observed in junctions without showing a zero-bias peak. We posit that the high negative magnetoresistance is due to the effect of a singlet-triplet Kondo effect under magnetic field originating from a double-quantum-dot system consisting of a Blatter radical molecule with a strong correlation to a second side-coupled molecule. Our findings not only provide the possibility of using the Blatter radical in a two-terminal system under cryogenic conditions but also reveal the magnetotransport properties emerging from different configurations of the molecule inside a junction.
format Preprint
id arxiv_https___arxiv_org_abs_2408_00366
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Singlet-Triplet Kondo Effect in Blatter Radical Molecular Junctions: Zero-bias Anomalies and Magnetoresistance
Mitra, Gautam
Zheng, Jueting
Schaefer, Karen
Deffner, Michael
Low, Jonathan Z.
Campos, Luis M.
Herrmann, Carmen
Costi, Theo A.
Scheer, Elke
Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
The Blatter radical has been suggested as a building block in future molecular spintronic devices due to its radical character and expected long-spin lifetime. However, whether and how the radical character manifests itself in the charge transport and magnetotransport properties seems to depend on the environment or has not yet been studied. Here, we investigate single-molecule junctions of the Blatter radical molecule in a mechanically controlled break junction device at low temperature. Differential conductance spectroscopy on individual junctions shows two types of zero-bias anomalies attributed to Kondo resonances revealing the ability to retain the open-shell nature of the radical molecule in a two-terminal device. Additionally, a high negative magnetoresistance is also observed in junctions without showing a zero-bias peak. We posit that the high negative magnetoresistance is due to the effect of a singlet-triplet Kondo effect under magnetic field originating from a double-quantum-dot system consisting of a Blatter radical molecule with a strong correlation to a second side-coupled molecule. Our findings not only provide the possibility of using the Blatter radical in a two-terminal system under cryogenic conditions but also reveal the magnetotransport properties emerging from different configurations of the molecule inside a junction.
title Singlet-Triplet Kondo Effect in Blatter Radical Molecular Junctions: Zero-bias Anomalies and Magnetoresistance
topic Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
url https://arxiv.org/abs/2408.00366