  We have characterized the vertical transport properties of epitaxial layered
structures composed of Pr$_{0.7}$Ca$_{0.3}$MnO$_{3}$ (PCMO) sandwiched between
SrRuO$_{3}$ (SRO) bottom electrode and several kinds of top electrodes such as
SRO, Pt, Au, Ag, and Ti. Among the layered structures, Ti/PCMO/SRO is distinct
due to a rectifying current-voltage ($I$--$V$) characteristic with a large
hysteresis. Corresponding to the hysteresis of the $I$--$V$ characteristics,
the contact resistance of the Ti/PCMO interface reversibly switches between two
stable states by applying pulsed voltage stress. We propose a model for the
resistance switching at the Ti/PCMO interface, in which the width and/or height
of a Schottky-like barrier are altered by trapped charge carriers in the
interface states.
