EXPERIMENTAL EVIDENCE OF A LOCKED VORTEX STATE IN TWINNED YBCO SINGLE CRYSTALS USING SI MECHANICAL MICRO-OSCILLATORS

D.J. PEREZ; PASTORIZA H; OSQUIGUIL E.; NIEVA G.; JUNG I. W.; LOPEZ D.

Congreso; 27th Intenational Conference on Low Temperature Conference; 2014

Transversal Meissner state is associated with the locking of the magnetic vortices along correlateddefects and constitutes the main prediction of the Bose-glass scaling theory, used to understand thevortex solid-to-liquid transition in high temperature superconductors. The experimentaldetermination of the existence of such a state is crucial to support or dispel the conclusions obtainedfrom scaling analysis of transport measurements near the transition line.We use micromechanical Si torsional oscillators to study this state in twinned YBa2Cu3O7-δ diskswhen the magnetic field is tilded away from the c axis. The quantitative features of our results isconsistent with ideal shielding of ab-plane field component Hab, as expected for the vortex state thatis fully locked to the twin boundaries.