Gauge field induced by ripples in graphene
  We study the effects of quenched height fluctuations (ripples) in graphene on the density of states (DOS). We show that at strong ripple disorder a divergence in the DOS can lead to an ordered ground state. We also discuss the formation of dislocations in corrugated systems, buckling effects in suspended samples, and the changes in the Landau levels due to the interplay between a real magnetic field and the gauge potential induced by ripples. 
F. Guinea, Baruch Horovitz and P. Le Doussal