Valley relaxation in a single-electron bilayer graphene quantum dot
- URL: http://arxiv.org/abs/2402.18328v1
- Date: Wed, 28 Feb 2024 13:49:14 GMT
- Title: Valley relaxation in a single-electron bilayer graphene quantum dot
- Authors: Lin Wang, Guido Burkard
- Abstract summary: We investigate the valley relaxation due to intervalley coupling in a single-electron bilayer graphene quantum dot.
The dominant valley relaxation channel in the high-field regime is the electron-phonon coupling via the deformation potential.
Interlayer hopping $gamma_3$ opens a valley relaxation channel for electric charge noise for rotationally symmetric quantum dots in bilayer graphene.
- Score: 6.5895924005488915
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: We investigate the valley relaxation due to intervalley coupling in a
single-electron bilayer graphene quantum dot. The valley relaxation is assisted
by both the emission of acoustic phonons via the deformation potential and
bond-length change mechanisms and $1/f$ charge noise. In the perpendicular
magnetic-field dependence of the valley relaxation time $T_1$, we predict a
monotonic decrease of $T_1$ at higher fields due to electron-phonon coupling,
which is in good agreement with recent experiments by Banszerus et al. We find
that the dominant valley relaxation channel in the high-field regime is the
electron-phonon coupling via the deformation potential. At lower fields, we
predict that a peak in $T_1$ can arise from the competition between $1/f$
charge noise and electron-phonon scattering due to bond-length change. We also
find that the interlayer hopping $\gamma_3$ opens a valley relaxation channel
for electric charge noise for rotationally symmetric quantum dots in bilayer
graphene.
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