Localization by particle-hole symmetry breaking: a loop expansion

Localization by a broken particle-hole (PH) symmetry in a random system of non-interacting quantum particles is studied on a d-dimensional lattice. Our approach is based on a chiral symmetry argument and the corresponding invariant measure, where the latter is described by a Grassmann functional integral. Within a loop expansion we find for small loops diffusion in the case of PH symmetry. Breaking the PH symmetry results in the creation of random dimers, which suppress diffusion and lead to localization on the scale root D/vertical bar mu vertical bar, where D is the effective diffusion coefficient at PH symmetry and mu is the parameter related to PH symmetry breaking.

Automated summary

This paper studies the localization phenomenon of non-interacting quantum particles in a random system based on the broken particle-hole (PH) symmetry. Using a chiral symmetry argument and a Grassmann functional integral, diffusion at PH symmetry and localization caused by breaking the PH symmetry are explored.