Transient laser-induced voltages in room-temperature films of YBa2Cu3O7−<i>x</i>

Abstract

Transient laser-induced electrical signals with peak voltages of ∼50 mV and &amp;lt;20 ns duration (full width half-maximum) have been observed in room-temperature thin films of YBa2Cu3O7−x in the absence of an applied current. It is demonstrated that the signal polarity is reversed when the films are illuminated through the substrate rather than at the air/film interface. The mechanism for this effect has yet to be elucidated.