Scanning microscopies of superconductors at very low temperatures
  We discuss basics of scanning tunneling microscopy and spectroscopy (STM/S) of the superconducting state with normal and superconducting tips. We present a new method to measure the local variations in the Andreev reflection amplitude between a superconducting tip and the sample. This method is termed Scanning Andreev Reflection Spectroscopy (SAS). We also briefly discuss vortex imaging with STM/S under an applied current through the sample, and show the vortex lattice as a function of the angle between the magnetic field and sample's surface. 
V. Crespo, A. Maldonado, J. A. Galvis, P. Kulkarni, I. Guillamon, J.   G. Rodrigo, H. Suderow, S. Vieira, S. Banerjee, P. Ro...
cond-mat.supr-con cond-mat.mes-hall