1. Enhanced Anisotropic Effective g Factors of an Al0.25Ga0.75N/GaN Heterostructure Based Quantum Point Contact
- Author
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Junxi Duan, Mariusz Graczyk, Shaoyun Huang, Fujun Xu, Fang-Chao Lu, Marcus Larsson, Bo Shen, Ning Tang, Weikun Ge, Ivan Maximov, and Sidong Liu
- Subjects
Physics ,education.field_of_study ,Zeeman effect ,Condensed matter physics ,Mechanical Engineering ,Quantum point contact ,Exchange interaction ,Population ,Bioengineering ,Heterojunction ,General Chemistry ,Chemical vapor deposition ,Condensed Matter Physics ,symbols.namesake ,symbols ,General Materials Science ,Metalorganic vapour phase epitaxy ,education ,Anisotropy - Abstract
Gate-defined quantum point contacts (QPCs) were fabricated with Al0.25Ga0.75N/GaN heterostructures grown by metal-organic chemical vapor deposition (MOCVD). In the transport study of the Zeeman effect, greatly enhanced effective g factors (g*) were obtained. The in-plane g* is found to be 5.5 ± 0.6, 4.8 ± 0.4, and 4.2 ± 0.4 for the first to the third subband, respectively. Similarly, the out-of-plane g* is 8.3 ± 0.6, 6.7 ± 0.7, and 5.1 ± 0.7. Increasing g* with the population of odd-numbered spin-splitted subbands are obtained at 14 T. This portion of increase is assumed to arise from the exchange interaction in one-dimensional systems. A careful analysis shows that not only the exchange interaction but the spin-orbit interaction (SOI) in the strongly confined QPC contributes to the enhancement and anisotropy of g* in different subbands. An approach to distinguish the respective contributions from the SOI and exchange interaction is therefore proposed.
- Published
- 2013
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