Numerical computation of the density of states for disordered magnetic chains

Abstract

Using the negative eigenvalue theorem we compute the density of magnon states for a disordered magnetic chain of 5 \ifmmode\times\else\texttimes\fi{} ${10}^{8}$ spins. Good agreement is obtained with the asymptotic expansion of the coherent potential approximation for a half-Gaussian distribution of nearest-neighbor interactions.