Quadratic electronic response of a two-dimensional electron gas

Article

关键词: STOPPING POWER;    ENERGY-LOSS;    CHARGED-PARTICLES;    HEAVY-PARTICLES;    SLOW IONS;    LIQUID;   

DOI  :  10.1103/PhysRevB.59.10145

来源: SCIE

【 摘 要 】

The electronic response of a two-dimensional (2D) electron system represents a key quantity in discussing one-electron properties of electrons in semiconductor heterojunctions, on the surface of liquid helium and in copper-oxide planes of high-temperature superconductors. We here report an evaluation of the wave-vector and frequency dependent dynamical quadratic density-response function of a 2D electron gas (2DEG), within a self-consistent field approximation. We use this result to find the Z(1)(3) correction to the stopping power of a 2DEG for charged particles moving at a fixed distance from the plane of the 2D sheet, Z(1) being the projectile charge. We reproduce, in the high-density limit, previous full nonlinear calculations of the stopping power of a 2DEG for slow antiprotons, and we go further to calculate the Z(1)(3) correction to the stopping power of a 2DEG for a wide range of projectile velocities. Our results indicate that linear-response calculations are, for all projectile velocities, less reliable in two dimensions than in three dimensions. [S0163-1829(99)00711-0].

【 授权许可】

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