Momentum-selective graphene spectroscopy of moiré excitons
Abstract
Far-field photoluminescence probes only the light-cone corner of an exciton's momentum content, whereas energy transfer to nearby graphene integrates in-plane momenta up to the inverse spacer thickness 1/z. For a WSe2/MoSe2 heterobilayer we build the transition polarization Pn(qv) of each localized moiré exciton from the registry-dependent vector dipole texture and use each Pn for both baths. The two baths rank the states differently: the graphene-rate ratios differ from the optical ones, their ordering inverts with spacer thickness, and the distance exponents at z=10\,nm spread by more than two units. These ratios are independent of the transition-dipole prefactor. Within the C3-symmetric leading-harmonic model the chiral p+ and d- states are also dark at normal incidence yet transfer to graphene at rates comparable to the bright ground state. Their graphene rate depends on the sign of the texture phase, a quantity invisible in far-field emission, which we determine from first principles. In a device this prediction requires a splitting, larger than the symmetry-breaking mixing, that protects the chiral partners. Graphene proximity thus acts as a momentum-selective near-field probe of moiré excitons, and we propose its use as a practical spectroscopy.
Related
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- Tensor-network methodology for real-space super-moiré excitons
- Room-temperature local strain control of moiré excitons in MoS2/WSe2 heterobilayers
- Hidden valley dynamics behind vanishing circular polarization in moiré excitons
- Momentum-Locked Edge Excitons in 2D Molecular Crystals
BibTeX
@misc{wakabayashi2026momentumselective,
title = {{Momentum-selective graphene spectroscopy of moiré excitons}},
author = {Katsunori Wakabayashi},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.33989},
eprint = {2610.33989},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.33989},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Momentum-selective graphene spectroscopy of moiré excitons
AU - Katsunori Wakabayashi
PY - 2026
DA - 2026/10/25
PB - arXiv
DO - 10.48550/arxiv.2610.33989
UR - https://arxiv.org/abs/2610.33989
AB - Far-field photoluminescence probes only the light-cone corner of an exciton's momentum content, whereas energy transfer to nearby graphene integrates in-plane momenta up to the inverse spacer thickness 1/z. For a WSe_2/MoSe_2 heterobilayer we build the transition polarization P_n(qv) of each localized moiré exciton from the registry-dependent vector dipole texture and use each P_n for both baths. The two baths rank the states differently: the graphene-rate ratios differ from the optical ones, their ordering inverts with spacer thickness, and the distance exponents at z=10\,nm spread by more than two units. These ratios are independent of the transition-dipole prefactor. Within the C_3-symmetric leading-harmonic model the chiral p_+ and d_- states are also dark at normal incidence yet transfer to graphene at rates comparable to the bright ground state. Their graphene rate depends on the sign of the texture phase, a quantity invisible in far-field emission, which we determine from first principles. In a device this prediction requires a splitting, larger than the symmetry-breaking mixing, that protects the chiral partners. Graphene proximity thus acts as a momentum-selective near-field probe of moiré excitons, and we propose its use as a practical spectroscopy.
ER -