Probing quasiparticle dynamics inBi2Sr2CaCu2O8+δwith a driven Josephson vortex lattice

Abstract

We show that the flux-flow transport of the Josephson vortex lattice (JVL) in layered high-temperature superconductors provides a convenient probe for both components of quasiparticle conductivity, $\sigma_{c}$ and $\sigma_{ab}$. We found that the JVL flux-flow resistivity, $\rho_{ff}$, in a wide range of magnetic fields is mainly determined by the in-plane dissipation. In the dense lattice regime ($B>1$ T) $\rho_{ff}(B)$ dependence is well fitted by the theoretical formula for that limit. That allows us to independently extract from the experimental data the values of $\sigma_{c}$ and of the ratio $\sigma _{ab}/(\sigma_{c}\gamma ^{4})$. The extracted temperature dependence $\sigma _{ab}(T)$ is consistent with microwave data. The shape of the current-voltage characteristics is also sensitive to the frequency dependence of $\sigma_{ab}$ and that allows us to estimate the quasiparticle relaxation time and relate it to the impurity bandwidth using data obtained for the same crystal.