Metalinsulator transitions in anisotropic twodimensional systems
Abstract
Several phenomena related to the critical behavior of noninteracting electrons in a disordered twodimensional tightbinding system with a magnetic field are studied. Localization lengths, critical exponents, and density of states are computed using transfermatrix techniques. Scaling functions of isotropic systems are recovered once the dimension of the system in each direction is chosen proportional to the localization length. It is also found that the critical point is independent of the propagation direction, and that the critical exponents for the localization length for both propagating directions are equal to that of the isotropic system, ν~73. We also calculate the critical value Λ_{c} of the scaling function for both the isotropic and the anisotropic system. It is found that Λ^{iso}_{c}=Λ^{x}_{c}Λ^{y}_{c}. Detailed numerical studies of the density of states n(E) for the isotropic system reveal that for an appreciable amount of disorder, the critical energy is off the band center.
 Publication:

Physical Review B
 Pub Date:
 February 2001
 DOI:
 10.1103/PhysRevB.63.085103
 arXiv:
 arXiv:condmat/0010430
 Bibcode:
 2001PhRvB..63h5103R
 Keywords:

 71.30.+h;
 71.55.Jv;
 Metalinsulator transitions and other electronic transitions;
 Disordered structures;
 amorphous and glassy solids;
 Condensed Matter  Disordered Systems and Neural Networks;
 Condensed Matter  Mesoscale and Nanoscale Physics
 EPrint:
 6 pages RevTeX, 6 figures included, submitted to Physical Review B