We studied the effects of impurities on Dirac fermions numerically. We used a tight-binding Hamiltonian of fermions with the magentic flux equal to π per plaquette for the model. A small amount of strong impurities create states near the zero energy and strong localization of these states is observed. Our results support a recent proposal of localization effects in a gapless d-wave superconductor.

• Received 8 June 1993

DOI:https://doi.org/10.1103/PhysRevB.48.4204