Peak effect in an irradiated microbridge of Bi-2212 single crystal: evidence for a Bragg Bose glass?

We have investigated I–V characteristics at very low temperature on a micro-bridge in a Bi-2212 single crystal with columnar defects patterned by laser ablation. We have shown that the critical current IC presents a maximum when increasing the applied magnetic field. This maximum is located below the matching field at a filling fraction f=BMax/BΦ=0.8. The transverse Meissner effect (TME) has also been checked by tilting the magnetic field away from the tracks. Contrary to the low field regime (f<0.8) where the vortex are strongly localized, the transverse component of the magnetic field is not screened anymore when the parallel one is higher than BMax. It suggests that the vortex system could be considered as a weak Bose glass with interstitial vortices. It suggests that the vortex system could be considered as a weak Bose glass with interstitial vortices. Finally, our results strongly support the existence of a typical vortex phase at low temperature and low magnetic field.