High magnetic field studies of two-dimensional electron gas in a GaN/GaAlN heterostructure: Mechanisms of parallel conduction
| Autor: | Wojciech Knap, Michel Goiran, Michael Shur, Eric Frayssinet, M. L. Sadowski, Sylvie Contreras |
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| Rok vydání: | 2001 |
| Předmět: |
Electron mobility
Condensed matter physics Magnetoresistance Chemistry General Physics and Astronomy Heterojunction Quantum Hall effect Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Shubnikov–de Haas effect Magnetic field Condensed Matter::Materials Science Band diagram Condensed Matter::Strongly Correlated Electrons Fermi gas |
| Zdroj: | Journal of Applied Physics. 89:1251-1255 |
| ISSN: | 1089-7550 0021-8979 |
| Popis: | We report on quantum Hall effect (QHE) and Shubnikov–de-Haas (SdH) measurements for a GaN/GaAlN heterostructure in high magnetic fields (up to 35 T). The observed well defined SdH oscillations, correlated with QHE plateaus, confirm the existence of a two-dimensional electron gas at the GaN/GaAlN interface. The Shubnikov–de-Haas oscillations are superimposed on a strong positive magnetoresistance. We show that this positive magnetoresistance can be linked to a parallel conduction channel. The analysis of the high magnetic field data yields information about the carrier concentration and mobility in this channel. The concentration and mobility of two-dimensional gas and the parallel conduction layer are analyzed in a wide temperature range (1.9–77 K). A physical model (based on the band diagram and mobility calculations) explaining the origin of parallel conduction is presented. |
| Databáze: | OpenAIRE |
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