Phase-slip-like resistivity in underdoped YBa2Cu3O7 -: art. no. 054502

We investigated the anomalous peak resistivity below the onset T-c in underdoped YBa2Cu3O7, reminiscent of that observed in one-dimensional (1D) wires of conventional superconductors. We performed measurements of the angular dependence of resistivity rho(theta) in a magnetic field and the temperature dependence of resistivity rho(T), which exhibit a peak for Bparallel to ab planes. This peak in rho(T) disappears for Bparallel to c axis. The width of the corresponding maximum in rho(theta) at theta=0degrees (Bparallel to ab planes) decreases with the increasing c-axis component of the field (B sin theta). The maximum in rho(theta) and rho(T) decreases with an increasing applied transport current. We analyzed the data using three different models of resistivity based on a 2D resistor array, flux motion, and thermally activated phase slips. Numerical calculations suggest that in a filamentary underdoped system, the phase-slip events could produce an anomalous resistivity close to T-c.