The vibrational densities of states for the diffusion-limited aggregate with varying elastic force consstants are calculated by the recursion method of Haydock, Heine and Kelly. It is found that the spectrum with central forces is very different from that with isotropic forces which is characterized by a power-law behaviour in the fraction frequency regime. An interesting crossover is also observed when the ratio of the central to the non-central force constants of the Born model varies from alpha/beta = 1 to alpha/beta = inifity.
部门归属
acad sinica,int ctr mat phys,shenyang 110015,peoples r china.;peng, gw (reprint author), wuhan univ,dept phys,wuhan 430072,peoples r china
修改评论