Delocalization of 2D Dirac Fermions: the Role of a Broken Supersymmetry
arXiv:cond-mat/9711097 · doi:10.1103/PhysRevLett.80.3113
Abstract
The mechanism of delocalization of two-dimensional Dirac fermions with random mass is investigated, using a superfield representation. Although localization effects are very strong, one fermion component can delocalize due to the spontaneous breaking of a special supersymmetry of the model. The delocalized fermion has a non-singular density of states and is decribed by a diffusion propagator. Supersymmetry is restored if the mean of the random mass is sufficiently large. This is accompanied by a critical boson component.
4 pages