Possible fluctuation origin of the anomalies in the C-axis magnetoresistance observed in bi2sr2cacu2o8+x above the critical-temperature

An expression for the transverse magnetoresistance above T-c has been derived from the theory of fluctuation contribution to the c-axis conductivity of layered superconductors under an external magnetic field,, which was recently developed by Dorin et al. The suppression of fluctuations due to the magnetic field leads to a decrease of the negative fluctuation contribution to the conductance, and therefore to a negative transverse magnetoresistance at temperatures not too close to T-c. The formula derived from the theory has been compared with the available experimental data of the magnetoresistance of BSCCO single crystals obtained by Ong et al. at temperatures 10-20 K above T-c. The quadratic increase of the relative magnetoresistance with the field and its temperature dependence are explained clearly. A quantitative fit to the experimental data shows a remarkable agreement of the theory with experiment, and allows to extract the values of several physical parameters.