Variable Temperature Scanning Laser Microscopy: A Novel Tool for Investigating Local Transport Properties

Chuhee Kwon, Department of Physics and Astronomy, California State University Long Beach

We have designed and built a variable temperature scanning laser microscope (VTSLM) to study the spatial distribution of electric transport properties of thin film samples.  A scanning laser microscope uses a focused laser beam to create a hot spot in a sample, which generates a voltage response as a function of the position of the laser beam.  The spatial distribution of transport properties in high temperature superconductor films was investigated using VTSLM.  We observed the spatial distributions of superconducting transition temperature (T_c) and critical current (I_c) as well as the current distribution in a non-uniform samples.  I will illustrate the capability of VTSLM and present our latest results in high temperature superconductivity.