| Autor: |
Gadelha, Andreij C., Nadas, Rafael, Barbosa, Tiago C., Watanabe, Kenji, Taniguchi, Takashi, Campos, Leonardo C., Raschke, Markus B., Jorio, Ado |
| Rok vydání: |
2022 |
| Předmět: |
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| Druh dokumentu: |
Working Paper |
| Popis: |
Due to its ultra-thin nature, the study of graphene quantum optoelectronics, like gate-dependent graphene Raman properties, is obscured by interactions with substrates and surroundings. For instance, the use of doped silicon with a capping thermal oxide layer limited the observation to low temperatures of a well-defined Kohn-anomaly behavior, related to the breakdown of the adiabatic Born-Oppenheimer approximation. Here, we design an optoelectronic device consisting of single-layer graphene electrically contacted with thin graphite leads, seated on an atomically flat hexagonal boron nitride (hBN) substrate and gated with an ultra-thin gold (Au) layer. We show that this device is optically transparent, has no background optical peaks and photoluminescence from the device components, and no generation of laser-induced electrostatic doping (photodoping). This allows for room-temperature gate-dependent Raman spectroscopy effects that have only been observed at cryogenic temperatures so far, above all the Kohn-anomaly phonon energy normalization. The new device architecture by decoupling graphene optoelectronic properties from the substrate effects, allows for the observation of quantum phenomena at room temperature. |
| Databáze: |
arXiv |
| Externí odkaz: |
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