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Abstract Selection rules are of vital importance in determining the basic optical properties of atoms, molecules and semiconductors. They provide general insights into the symmetry of the system and the nature of relevant electronic states. A two-dimensional electron gas in a magnetic field is a model system where optical transitions between Landau levels (LLs) are described by simple selection rules associated with the LL indexN. Here we examine the inter-LL optical transitions of high-quality bilayer graphene by photocurrent spectroscopy measurement. We observed valley-dependent optical transitions that violate the conventional selection rules Δ|N| = ± 1. Moreover, we can tune the relative oscillator strength by tuning the bilayer graphene bandgap. Our findings provide insights into the interplay between magnetic field, band structure and many-body interactions in tunable semiconductor systems, and the experimental technique can be generalized to study symmetry-broken states and low energy magneto-optical properties of other nano and quantum materials.
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This content will become publicly available on August 26, 2026
Spin-coated Ge–In–Se thin films: characterization and changes induced by visible and electron radiation in relation to indium content
The Ge–In–Se thin films were prepared in high optical qualityviaspin-coating and their surface was patterned using electron beam lithography and optical holography.
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- Award ID(s):
- 2106457
- PAR ID:
- 10638117
- Publisher / Repository:
- Royal Society of Chemistry
- Date Published:
- Journal Name:
- Materials Advances
- Volume:
- 6
- Issue:
- 17
- ISSN:
- 2633-5409
- Page Range / eLocation ID:
- 6152 to 6161
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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