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Three Subband Occupation of the Two‐Dimensional Electron Gas in Ultrathin Barrier AlN/GaN Heterostructures
Author(s) -
Yang Liuyun,
Wang Xinqiang,
Wang Tao,
Wang Jingyue,
Zhang Wenjie,
Quach Patrick,
Wang Ping,
Liu Fang,
Li Duo,
Chen Ling,
Liu Shangfeng,
Wei Jiaqi,
Yang Xuelin,
Xu Fujun,
Tang Ning,
Tan Wei,
Zhang Jian,
Ge Weikun,
Wu Xiaosong,
Zhang Chi,
Shen Bo
Publication year - 2020
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.202004450
Subject(s) - heterojunction , fermi gas , materials science , molecular beam epitaxy , condensed matter physics , quantum well , shubnikov–de haas effect , electron , scattering , electron density , quantum hall effect , physics , epitaxy , quantum oscillations , nanotechnology , optics , quantum mechanics , layer (electronics) , laser
Ultrathin barrier AlN/GaN heterostructure with record low sheet resistance of 82 Ω sq −1 is achieved by molecular beam epitaxy, where Shubnikov‐de Haas oscillations (SdHOs) and quantum Hall effect (QHE) of two‐dimensional electron gas (2DEG) are observed. The fast Fourier transform analysis of the SdHOs demonstrates a three‐subband occupation in the triangle quantum well for the first time, with the electron density of n 1 = 2.2 × 10 13 cm −2 , n 2 = 2.3 × 10 12 cm −2 , and n 3 = 8.8 × 10 11 cm −2 , respectively, and the corresponding energy of 265, 28, and 11 meV below Fermi level. The three‐subband QHE with a superposed feature is also demonstrated for the first time in AlN/GaN heterostructure, with large filling factors at high electron densities. By analyzing the first subband as the dominant part of the superposed QHE, the transport physics of a special magneto‐intersubband scattering is revealed. These results contribute to a better understanding of the quantum physics for 2DEG, leading to a versatile functionality for AlN/GaN devices.