2003/12/02 by J. C. Cao
Physics and Astronomy · #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.91.237401
published as J. C. Cao, Physical Review Letters 91, 237401 (2003) · 4 pages including 3 EPS figs
arxiv created 2003/12/02 · arxiv updated 2009/12/01
We have theoretically investigated nonlinear free-carrier absorption of terahertz radiation in InAs/AlSb heterojunctions. By considering multiple photon process and conduction-valence interband impact ionization (II), we have determined the field and frequency dependent absorption rate. It is shown that (i) electron-disorder scatterings are important at low to intermediate field, and (ii) most importantly, the high field absorption is dominated by II processes. Our theory can satisfactorily explain a long standing experimental result on the nonlinear absorption in THz regime.