Critical behavior of ac conductivity near the Anderson transition

[摘要] We investigate the dynamic scaling behavior of ac conductivity sigma(omega) in three-dimensional (3D) unitary and symplectic systems in addition to orthogonal one by means of large-scale simulations. It is demonstrated that the ac conductivity near the Anderson transition behave as sigma(omega)proportional to omega(delta)(delta similar or equal to 1/3) for all of the above systems. Numerical calculations are performed by an efficient algorithm based on the forced oscillator method (FOM), which enables us to accurately treat large-scale quantum systems with less computational effort. The values of the exponents delta are determined by the finite-time scaling method for the FOM. [S0163-1829(99)11943-X].

[关键词] DISORDERED-SYSTEMS;MOBILITY EDGE;LOCALIZATION;DIFFUSION;ELECTRONS;STATISTICS;SYMMETRY