Plasmons and intersubband resonances in quasi two-dimensional systems: Nonlocal coupling and lineshapes

✍ Scribed by D.H. Ehlers

• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 383 KB
• Volume: 5
• Category: Article
• ISSN: 0749-6036
• DOI: 10.1016/0749-6036(89)90297-8

✦ Synopsis

For accumulation layers at n-GaAs interfaces the nonlocal electronic susceptibility has been calculated within the RPA. An analysis of resulting theoretical charge and spin density fluctuation spectra and also profiles of the complex induced potential inside the quasi two-dimensional electron gas reveal new insights into nonlocal coupling mechanisms and the internal structure of the collective modes. The dispersion and lineshape of two-dimensional (2D) plasmons reflect a strong nonlocal coupling to the collective mode of intersubband transitions.

These intersubband plasmons show considerable Landau damping and dispersion.

Its wellknown depolarisation shift at small 91 we find to be strongly influenced by the spectral proximity of the continuum of states. The shift is only half of the value predicted by the widely used two-band models.