Journal Article

FZJ-2026-01631

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Phonon-limited valley lifetimes in single-particle bilayer graphene quantum dots

Banszerus, L.FZJ*RWTH* ; Hecker, K.FZJ*RWTH* ; Wang, L. ; Möller, S.FZJ*RWTH* ; Watanabe, K. ; Taniguchi, T. ; Burkard, G. ; Volk, C.FZJ* ; Stampfer, C. (Corresponding author)FZJ*

2025
Inst. Woodbury, NY

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Please use a persistent id in citations: doi:10.1103/dkgn-pfjb  doi:10.34734/FZJ-2026-01631

Abstract: The valley degree of freedom in two-dimensional (2D) semiconductors, such as gapped bilayer graphene (BLG) and transition metal dichalcogenides, is a promising carrier of quantum information in the emerging field of valleytronics. While valley dynamics have been extensively studied for moderate band gap 2D semiconductors using optical spectroscopy techniques, very little is known about valley lifetimes in narrow band gap BLG, which is difficult to study using optical techniques. Here, we report single-particle valley relaxation times 𝑇1exceeding several microseconds in electrostatically defined BLG quantum dots using a pulse-gating technique. The observed dependence of 𝑇1on perpendicular magnetic field can be understood qualitatively and quantitatively by a model in which 𝑇1is limited by electron-phonon coupling. We identify the coupling to acoustic phonons via the bond length change and via the deformation potential as the limiting mechanisms.

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Contributing Institute(s):

1. Halbleiter-Nanoelektronik (PGI-9)
2. JARA-FIT (JARA-FIT)

Research Program(s):

1. 5222 - Exploratory Qubits (POF4-522) (POF4-522)
2. 2D4QT - 2D Materials for Quantum Technology (820254) (820254)
3. DFG project G:(GEPRIS)390534769 - EXC 2004: Materie und Licht für Quanteninformation (ML4Q) (390534769) (390534769)

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Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Electronics and Telecommunications Collection ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF < 5 ; JCR ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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