The Plasmon In Two-dimentional Electron Gas Of GaN Heterstructure

The physical properties of low dimensional Semiconductor is very important in the field of condensed matter physics, the special physical properties of the structure have extensive application prospects in ophotoelectronic devices. The material of group-III-nitride has rich connotation of physics and is an ideal structure to research low dimensional system. AlGaN/GaN heterojunction has become a new hot spot in the present due to its high concentration of two-dimensional electron gas. The polarization effect cannot be ignored to the formation and accommodation of2DEG at the interface of AlGaN/GaN heterojunction. This article obtains the wave function and energy level distribution through the self-consistent method.This paper explains the physical phenomena of a low dimensional system by researching the nature of plasmon. Plasmon in the low dimensional structure is a long-range excitation from the interaction between electrons, which can reveal the electron-electron interaction mechanism and multi-body effect.This paper mainly studies the existence conditions of plasmon in the channel of two-dimensional electron gas of AlGaN/GaN heterojunction. On the basis of the triangle trap, the nature of plasmon in the two dimensional electron gas has been studied through the phase approximation method (RPA), dielectric function tensor theory and linear response theory. On the basis of dielectric function tensor theory, we have got the existing conditions of the single particle excitation and the collective excitation in the two-subband and three-subband model. In the two-subband model, intersubband collective excitation of subbands1and2is obtained. We also obtained the intrasubband collective excitation of ground state. However, collective excitation only exist in long wave approximation;with the reduce of wavelength, collective excitation coupled to the single particle excitation area. In the three-subband model, we have not only got the same area as the two-subband model, but also obtained the existing conditions of plasmon coupled by three energy levels.