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摘要
The investigation on disorder-driven metal-insulator transition of the Anderson lattice model has been extended to a CsCl-type complex lattice to accommodate for the hybridized bands originating from atomic orbitals of inequivalent lattice sites. Using the standard transfer-matrix method and finite-size scaling an asymmetrical mobility edge is found in the energy-disorder phase diagram under site-selective disorder. The critical disorder is larger in the less disorder-affected band than its counterpart in the more disorder-affected band. Moreover, a unique type of delocalized state appears at the edge of the less disorder-affected band. The asymptotic localization length lambda(M)(W) increases linearly with the longitudinal sample size, which depends neither on the lateral size M nor on the disorder strength W. Except for this particular energy, metal-insulator transitions exist for all other energies and reduced localization lengths satisfy the single-parameter scaling law. The critical exponent, nu approximate to 1.5-1.6, is in good agreement with the previous results. The critical disorder is larger than that of a simple cubic lattice due to increased coordination number. The complex Anderson lattice model considered here has the advantage of simulating the localization disparity between electron-and hole-doped bands in the presence of site-selective disorder.
- 出版日期2010-2
- 单位南京大学
