Fermion condensation around a Coulomb impurity in a Weyl semimetal and   in a narrow band gap semiconductor as manifestations of the Landau   zero-charge problem
  A Coulomb impurity placed in an undoped Weyl semimetal spontaneously surrounds itself with a cloud of condensed Weyl fermions. We find that the ground-state of this system exhibits an experimentally accessible Landau zero-charge effect: the fermion condensate completely screens out the impurity charge. In a narrow band gap semiconducor this effect manifests itself in the near universality of observable charge of a highly-charged recombination center. 
Eugene B. Kolomeisky and Joseph P. Straley
cond-mat.mes-hall hep-th