FRACTION DENSITY OF STATES BY THE MAXIMUM-ENTROPY METHOD

被引：4

作者：

EVANGELOU, SN ^{[1
]}

PAPANICOLAOU, NI ^{[1
]}

ECONOMOU, EN ^{[1
]}

机构：

[1] INST ELECTR STRUCT & LASERS,FDN RES & TECHNOL,CRETE RES CTR,IRAKLION,GREECE

来源：

PHYSICAL REVIEW B | 1991年 / 43卷 / 13期

关键词：

D O I：

10.1103/PhysRevB.43.11171

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We present a study of the one-magnon density of states in the three-dimensional dilute Heisenberg ferromagnet. The ensemble-averaged density of states is evaluted by calculating a small number of spectral moments and employing a maximum-entropy criterion. Finite-size-lattice data, via common numerical simulation techniques, are also presented. The results demonstrate the fraction excitations at the percolation concentration p(c) as expected from the Alexander-Orbach conjecture and show the presence of the magnon-to-fracton crossover. At the percolation threshold p(c), we estimate a value for the spectral dimension of d(s) almost-equal-to 1.52. The corresponding problem of phonons in random materials is also discussed in connection with the available experimental data.

引用

页码：11171 / 11176

页数：6