Impact of competing energy scales on the shell-filling sequence in elliptic bilayer graphene quantum dots
Impact of competing energy scales on the shell-filling sequence in elliptic bilayer graphene quantum dots
We report on a detailed investigation of the shell-filling sequence in electrostatically defined elliptic bilayer graphene quantum dots (QDs) in the regime of low charge carrier occupation, N≤12, by means of magnetotransport spectroscopy and numerical calculations. We show the necessity of including...
Saved in:
Personal Name(s): | Möller, Sören |
---|---|
Banszerus, L. / Knothe, A. / Valerius, L. / Hecker, K. / Icking, E. / Watanabe, K. / Taniguchi, T. / Volk, Christian / Stampfer, C. (Corresponding author) | |
Contributing Institute: |
Halbleiter-Nanoelektronik; PGI-9 |
Published in: | Physical review / B, 108 (2023) 12, S. 125128 |
Imprint: |
Woodbury, NY
Inst.
2023
|
DOI: |
10.1103/PhysRevB.108.125128 |
DOI: |
10.34734/FZJ-2024-03012 |
Document Type: |
Journal Article |
Research Program: |
EXC 2004: Materie und Licht für Quanteninformation (ML4Q) 2D Materials for Quantum Technology Graphene Flagship Core Project 3 Exploratory Qubits |
Link: |
OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://dx.doi.org/10.34734/FZJ-2024-03012 in citations.
We report on a detailed investigation of the shell-filling sequence in electrostatically defined elliptic bilayer graphene quantum dots (QDs) in the regime of low charge carrier occupation, N≤12, by means of magnetotransport spectroscopy and numerical calculations. We show the necessity of including both short-range electron-electron interaction and wave-function-dependent valley g-factors for understanding the overall fourfold shell-filling sequence. These factors lead to an additional energy splitting at half filling of each orbital state and different energy shifts in out-of-plane magnetic fields. Analysis of 31 different bilayer graphene (BLG) QDs reveals that both valley g-factor and electron-electron interaction-induced energy splitting increase with decreasing QD size, validating theory. However, we find that the electrostatic charging energy of such gate-defined QDs does not correlate consistently with their size, indicating complex electrostatics. These findings offer significant insights for future BLG QD devices and circuit designs. |