ISSN:
1572-9613
Keywords:
Density of state tails
;
spontaneous symmetry breaking
;
optimum fluctuation method
;
degenerate energy bands
;
virial theorem for nonlinear functionals
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract The optimum fluctuation method (OFM) has been applied to the tails of the density of states, arising near the edges of the spherically symmetric degenerate bands. In this case the optimum fluctuations (OF) have been shown to undergo a qualitative change, as compared to the case of nondegenerate bands, they lose the spherical symmetry and become elongated or flattened. This means that spontaneous breaking of symmetry takes place. In addition to the usual mechanism of tailing due to the potential of impurities, another mechanism connected with the field of random deformations, arising due to difference in the size of the guest and host atoms, has been also considered. The method used for treating this problem is intimately related to the techniques of the theory of self-trapping. The density of states in the tails, and in some cases the shape of OFs, have been found for all the cases under consideration.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01017864
Permalink
