Physics – Mathematical Physics
Scientific paper
2004-06-22
Physics
Mathematical Physics
17 pages, 3 figures
Scientific paper
10.1007/s00220-005-1304-y
We consider network models of quantum localisation in which a particle with a two-component wave function propagates through the nodes and along the edges of an arbitrary directed graph, subject to a random SU(2) rotation on each edge it traverses. The propagation through each node is specified by an arbitrary but fixed S-matrix. Such networks model localisation problems in class C of the classification of Altland and Zirnbauer, and, on suitable graphs, they model the spin quantum Hall transition. We extend the analyses of Gruzberg, Ludwig and Read and of Beamond, Cardy and Chalker to show that, on an arbitrary graph, the mean density of states and the mean conductance may be calculated in terms of observables of a classical history-dependent random walk on the same graph. The transition weights for this process are explicitly related to the elements of the S-matrices. They are correctly normalised but, on graphs with nodes of degree greater than 4, not necessarily non-negative (and therefore interpretable as probabilities) unless a sufficient number of them happen to vanish. Our methods use a supersymmetric path integral formulation of the problem which is completely finite and rigorous.
No associations
LandOfFree
Network Models in Class C on Arbitrary Graphs does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Network Models in Class C on Arbitrary Graphs, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Network Models in Class C on Arbitrary Graphs will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-669917