Observation of a local conductivity in vortex liquid regime of YBa2Cu3O7−δ single crystal

We attached two current contacts and two voltage contacts on both sides of MTG-YBCO single crystals, and performed transport measurement applying the current parallel and perpendicular to the CuO2 layers in the case of the applied magnetic field up to 7.5 T parallel to the c axis. The results show that in the dissipative regime, the voltage signal on the side of the applied current contacts is larger than that on the opposite side, and the ratio of voltage signals increases at first and then decreases with decreasing temperature. The temperature dependence of resistivity along the c axis is consistent with that in the ab plane. The critical temperature Tcc along the c axis is higher than that in the ab plane, indicating that the coupling between the layers is stronger as the temperature decreases, and a 3D character is seen at lower temperature.