Novel Vortex Solid State in YBa${}_2$Cu${}_3$O${}_{7-\delta }$ Twinned Crystals

Abstract

We report on the scaling of transport properties around the vortex melting in YBa${}_2$Cu${}_3$O${}_{7-\delta }$ oriented-twin single crystals in applied magnetic fields between 1T and 18T. We find that for all the measured field range the linear resistivity scales as $\rho (t,\theta )\sim t^{sy}{\mathcal{F}}_{\pm }(\sin (\theta )t^{-sx})$, with $t=|T-T_{BG}|$ and $\theta$ the angle between de planar defects and the magnetic field. The scaling is valid only for angles where the transition temperature $T_{BG}(\theta )$ shows a cusp. The critical exponents $sx$ and $sy$ are in agreement with the values predicted by Lidmar and Wallin only at magnetic fields below 4T. A change in the value of $sx$ from $sx=1\pm 0.2$ to $sx=3\pm 0.2$ at around $H^{cr}\approx$ 4T when the magnetic field is increased, is responsible for changes in the shape of the $T_{BG}(\theta )$ curve and in the dependence of the linear dissipation on temperature and angle. The results strongly suggest the existence of a different vortex glassy phase in twinned crystals compared to the Bose-glass state found in samples with linear defects.

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Cited by in corpus (2)

• Novel dynamics and critical currents in fast superconducting vortices at high pulsed magnetic fields
• Thermodynamic evidence for the Bose glass transition in twinned YBa${}_2$Cu${}_3$O${}_{7-\delta }$ crystals