中国物理B ›› 2009, Vol. 18 ›› Issue (9): 3905-3908.doi: 10.1088/1674-1056/18/9/048

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Influence of applied electric field on the absorption coefficient and subband distances in asymmetrical AlN/GaN coupled double quantum wells

岑龙斌, 沈波, 秦志新, 张国义   

  1. State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
  • 收稿日期:2008-12-29 修回日期:2009-04-07 出版日期:2009-09-20 发布日期:2009-09-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos 60806042, 10774001, 60736033, 60890193 and 60628402), National Basic Research Program of China (Grant Nos 2006CB604908 and 2006CB921607), the Research Fund for the Doctoral Program of Higher Education in China (Grant Nos 200800011021 and 20060001018), and Beijing Natural Science Foundation (Grant No 4062017).

Influence of applied electric field on the absorption coefficient and subband distances in asymmetrical AlN/GaN coupled double quantum wells

Cen Long-Bin(岑龙斌), Shen Bo(沈波)†, Qin Zhi-Xin(秦志新), and Zhang Guo-Yi(张国义)   

  1. State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
  • Received:2008-12-29 Revised:2009-04-07 Online:2009-09-20 Published:2009-09-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos 60806042, 10774001, 60736033, 60890193 and 60628402), National Basic Research Program of China (Grant Nos 2006CB604908 and 2006CB921607), the Research Fund for the Doctoral Program of Higher Education in China (Grant Nos 200800011021 and 20060001018), and Beijing Natural Science Foundation (Grant No 4062017).

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摘要： The influence of applied electric fields on the absorption coefficient and subband distances in asymmetrical AlN/GaN coupled double quantum wells (CDQWs) has been investigated by solving Schr?dinger and Poisson equations self-consistently. It is found that the absorption coefficient of the intersubband transition (ISBT) between the ground state and the third excited state (1odd-2even) can be equal to zero when the electric fields are applied in asymmetrical AlN/GaN CDQWs, which is related to applied electric fields induced symmetry recovery of these states. Meanwhile, the energy distances between 1odd-2even and 1even-2even subbands have different relationships from each other with the increase of applied electric fields due to the different polarization-induced potential drops between the left and the right wells. The results indicate that an electrical-optical modulator operated within the opto-communication wavelength range can be realized in spite of the strong polarization-induced electric fields in asymmetrical AlN/GaN CDQWs.

Abstract: The influence of applied electric fields on the absorption coefficient and subband distances in asymmetrical AlN/GaN coupled double quantum wells (CDQWs) has been investigated by solving Schr?dinger and Poisson equations self-consistently. It is found that the absorption coefficient of the intersubband transition (ISBT) between the ground state and the third excited state (1odd-2even) can be equal to zero when the electric fields are applied in asymmetrical AlN/GaN CDQWs, which is related to applied electric fields induced symmetry recovery of these states. Meanwhile, the energy distances between 1odd-2even and 1even-2even subbands have different relationships from each other with the increase of applied electric fields due to the different polarization-induced potential drops between the left and the right wells. The results indicate that an electrical-optical modulator operated within the opto-communication wavelength range can be realized in spite of the strong polarization-induced electric fields in asymmetrical AlN/GaN CDQWs.

Key words: AlN/GaN CDQWs, electrical--optical modulator, intersubband transition

中图分类号:  (Quantum wells)

  • 78.67.De
42.79.Hp (Optical processors, correlators, and modulators) 42.79.Sz (Optical communication systems, multiplexers, and demultiplexers?) 42.79.Ta (Optical computers, logic elements, interconnects, switches; neural networks)