Theory of Scanning Tunneling Microscopy Probe of Impurity States in a<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>D</mml:mi></mml:math>-Wave Superconductor

Abstract

Scanning tunneling microscopy can provide a probe for the detailed study of quasiparticle states in high-${T}_{c}$ superconductors. We propose that it can also be used to acquire specific information about impurity-induced quasiparticle states and the superconducting order-parameter structure. In particular, the local density of states is found to be sensitive to impurity-induced resonances and to the symmetry of the order parameter.