Unraveling of free carrier absorption for terahertz radiation in heterostructures

Abstract

The relation between free carrier absorption and intersubband transitions in semiconductor heterostructures is resolved by comparing a sequence of structures. Our numerical and analytical results show how free carrier absorption evolves from the intersubband transitions in the limit of an infinite number of wells with vanishing barrier width. It is explicitly shown that the integral of the absorption over frequency matches the value obtained by the f-sum rule. This shows that a proper treatment of intersubband transitions is fully sufficient to simulate the entire electronic absorption in heterostructure THz devices.

6 pages, accepted by Physical Review B

References in corpus (1)

• Quantum-mechanical wavepacket transport in quantum cascade laser structures

Cited by in corpus (6)

• Modeling techniques for quantum cascade lasers
• Contrasting influence of charged impurities on transport and gain in terahertz quantum cascade lasers
• Free carrier absorption in quantum cascade structures
• Relevance of intra- and inter-subband scattering on the absorption in heterostructures
• Negative free carrier absorption in terahertz quantum cascade lasers
• Free carrier absorption in cascade structures due to static scatterers in the in-plane polarization