Chiral metal as a ferromagnetic super spin chain
Abstract
The electrons on the surface of a disordered multilayer integer quantum Hall system constitute an unusual chiral metal with ballistic motion transverse to the field, and diffusive motion parallel to it. We present a nonperturbative analytic treatment of an appropriate model, consisting of disordered chiral fermions in two dimensions. A supersymmetric generating functional is set up for the correlation functions of this system. The strong disorder limit is mapped into a supersymmetric spin chain, with ferromagnetic exchange coupling, reflecting the electron's chiral motion. The ferromagnetic ground state and the spin wave excitations, corresponding to the diffusion modes of the chiral metal, are found exactly. The parametric density of states correlator in the ergodic limit is computed from a Boltzmannweighted sum over lowenergy spin states. The result is of a universal form and coincides with that for a hermitian random matrix.
 Publication:

Nuclear Physics B
 Pub Date:
 February 1997
 DOI:
 10.1016/S05503213(96)00572X
 arXiv:
 arXiv:condmat/9608049
 Bibcode:
 1997NuPhB.483..601B
 Keywords:

 Condensed Matter
 EPrint:
 34 pages, LaTeX with two figures included via epsf. Replacement corrects an error in the section (5.5) on parametric correlations. Complete postscript file available also at http://www.itp.ucsb.edu/~balents/papers.html