Condensed Matter Seminar

Vagharsh Mkhitaryan
University of Utah

Tuesday, January 27, 2009; 4:00 pm in JFB 334

Site Percolation on Triangular Lattice: Novel Network Model for the Integer Quantum Hall Transition

Common approach to the theoretical study of the quantum Hall transition is the Chalker-Coddington network model on the square lattice. We introduce a new version of the network model formulated on the triangular lattice, where the scattering at the sites is described by 3x3 matrix. Extending renormalization-group description of the classical site percolation to the quantum case, we derive a closed equation for the distribution function of conductance. Solving this equation numerically, we get for the critical exponent of the correlation radius ν ≈ 2.3-2.76, in good agreement with established value ν=2.33.