Open AccessRANDOM SYSTEMS WITH INHOMOGENEOUS CONCENTRATION
Author(s) -
Zhao-Qing Zhang
Publication year - 1980
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.29.1193
Subject(s) - binary number , physics , limit (mathematics) , particle system , constant (computer programming) , function (biology) , order (exchange) , superlattice , modulation (music) , statistical physics , energy (signal processing) , condensed matter physics , quantum mechanics , mathematical analysis , mathematics , computer science , arithmetic , finance , evolutionary biology , acoustics , economics , biology , programming language , operating system
The methods of configurational average of ensemble on a homogeneously random binary system is extended to treat a conditionally random binary system, where the concentration of one species c(r) is not a constant but modulated in a certain way. A restricted ensemble is chosen to describe such a system, the corresponding generalized CPA equation is derived. If we separate c(r) into c and δc(r), a decomposition scheme is introduced to average the uniform part c and deviation part dc successively. For a sinusoidal modulation, the averaged single-particle Green's function and its self-energy are calculated formally to the second order in δc/c. In the virtual crystal limit, the band splitting character of a superlattice is recovered.