Journal article Phonon-limited valley lifetimes in single-particle bilayer graphene quantum dots
L. Banszerus (author) (Search by this author)
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K. Hecker (author) (Search by this author)
;
L. Wang (author) (Search by this author)
;
S. Möller (author) (Search by this author)
;
K. Watanabe (author) (Search by this author)
ORCID https://orcid.org/0000-0003-3701-8119
National Institute for Materials Science
SAMURAI NIMS Researchers Directory SAMURAI
ORCID SAMURAI ;
T. Taniguchi (author) (Search by this author)
ORCID https://orcid.org/0000-0002-1467-3105
National Institute for Materials Science
SAMURAI NIMS Researchers Directory SAMURAI
ORCID SAMURAI ;
G. Burkard (author) (Search by this author)
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C. Volk (author) (Search by this author)
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C. Stampfer (author) (Search by this author)
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Citation
L. Banszerus, K. Hecker, L. Wang, S. Möller, K. Watanabe, T. Taniguchi, G. Burkard, C. Volk, C. Stampfer. Phonon-limited valley lifetimes in single-particle bilayer graphene quantum dots. Physical Review B. 2025, 112 (3), 035409. https://doi.org/10.1103/dkgn-pfjb

Description:

(abstract)

The valley degree of freedom in honeycomb crystals such as 2D semiconductors, graphene and bilayer graphene (BLG) is a promising carrier of quantum information alongside spin and charge. This is all the more true since gate- controlled single-particle quantum dots (QDs) have been demonstrated in bilayer graphene, paving the way for the realisation of spin and valley qubits. Although long spin relaxation times have recently been reported in BLG QDs, nothing is known about single-particle valley lifetimes. Here we report single-particle valley relaxation times (T1 times) exceeding several microseconds in electrostatically defined BLG QDs. The observed dependence of T1 on the perpendicular magnetic field can be understood qualitatively and quantitatively by a model in which T1 is limited by electron-phonon coupling. We identify coupling to acoustic phonons via the bond length change and via the deformation potential as the limiting mechanisms.

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Keyword: bilayer graphene quantum dots
, valley lifetime, electron-phonon coupling

Date published: 2025-07-10

Publisher: American Physical Society (APS)

Journal:

  • Physical Review B (ISSN: 1550235X) vol. 112 issue. 3 p. 35409-35409 035409

Funding:

  • Deutsche Forschungsgemeinschaft STA 1146/11-1
  • Deutsche Forschungsgemeinschaft 425217212
  • Deutsche Forschungsgemeinschaft 425217212
  • Japan Society for the Promotion of Science 21H05233
  • Japan Society for the Promotion of Science 23H02052
  • Core Research for Evolutional Science and Technology JPMJCR24A5
  • Ministry of Education, Culture, Sports, Science and Technology
  • European Research Council 820254
  • Deutsche Forschungsgemeinschaft EXC 2004/1-390534769

Manuscript type: Publisher's version (Version of record)

MDR DOI:

First published URL: https://doi.org/10.1103/dkgn-pfjb

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Updated at: 2026-05-11 13:42:33 +0900

Published on MDR: 2026-05-11 16:25:08 +0900

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