We attached two current and two voltage contacts on both sides of ${\mathrm{Bi}}_2$${\mathrm{Sr}}_2$${\mathrm{CaCu}}_2$${\mathrm{O}}_{\mathit{x}}$ single crystals and performed transport measurements applying the current parallel to the ${\mathrm{CuO}}_2$ layers. In the Ohmic regime, the voltage signal on the side of the current contacts was more than a factor of 100 larger than at the opposite side. The results are interpreted within an anisotropic resistivity model to obtain the true resistivities ${\mathrm{\rho }}_{\mathit{a}\mathit{b}}$(B,T) and ${\mathrm{\rho }}_{\mathit{c}}$(B,T). A model is presented based on the movement of pancake vortices involving vortex shear, vortex cutting, and generation of Josephson vortices between the layers.

• Received 10 April 1992

DOI:https://doi.org/10.1103/PhysRevLett.69.522