Ballistic quasiparticle propagation and symmetry of the superconducting order parameter

We suggest to use the ballistic propagation of quasiparticles in anisotropic superconductors to identify the symmetry of the superconducting order parameter. An array of tunneling junctions is proposed to detect the quasiparticles injected by a point contact. We interpret the resulting pattern as a real-space image of the wave-vector dependent superconducting gap. (orig.)