Dynamical conductivity of type-I semiconductor superlattices

✍ Scribed by A.C. Sharma; Aruna Bajpai

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 273 KB
• Volume: 28
• Category: Article
• ISSN: 0749-6036
• DOI: 10.1006/spmi.1999.0779

✦ Synopsis

We calculated longitudinal and transverse macroscopic as well as microscopic dynamical conductivity for a modulation-doped type-I superlattice. Our computed long wavelength macroscopic conductivity significantly differs from Drude conductivity in the low-frequency regime (microwave and infrared radiations). Macroscopic conductivity shows oscillatory behaviour along the direction of growth of the superlattice. Propagation of transverse electromagnetic waves in a superlattice has been studied for all possible values of frequency and wavevector. It is found that microscopic transverse conductivity exhibits poles along both real and imaginary axes of frequency. Depending on the values of wavevector components, along and perpendicular to the direction of the superlattice, both poles can lie on real or imaginary axes of frequency. We also find that there can be more than one penetration depth for a superlattice and one of them decreases with frequency for frequencies below the microwave regime.