Formation of vortex line around the glass transition in YBa₂Cu₃O_7−δ films

Abstract

Two components of current-induced electric fields in ab plane, E_x and E_y, have been measured simultaneously on YBCO(123) films around the glass transition temperature T_g in magnetic fields H with components (H₀, H₀, 0.1H₀), where x and y axes are parallel to the direction of the current density and c axis, respectively. In this condition, a finite transverse field Ey almost equal to E_x can be observed if the vortex lines form and move along the Lorentz force. In each H, the ratio ¦E_y/E_x¦ at a low current limit, which is zero far above T_g, increases in the critical region and transfers to unity below T_g. Our results indicate that the vortices become lines with long range correlation along H direction at the vortex glass transition without receiving the effect of the intrinsic pinning.