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Magnetoresistance of YBa2Cu3O7 in the "cold spots" model

Research paper by Anatoley T. Zheleznyak, Victor M. Yakovenko, H. D. Drew

Indexed on: 17 Aug '98Published on: 17 Aug '98Published in: Physics - Superconductivity



Abstract

We calculate the in-plane magnetoresistance $\Delta\rho_{xx}/\rho_{xx}$ of YBa$_2$Cu$_3$O$_7$ in a magnetic field applied perpendicular to the $CuO_2$ planes for the ``cold spots'' model. In this model, the electron relaxation time $\tau_2\propto1/T^2$ at small regions on the Fermi surface near the Brillouin zone diagonals is much longer than the relaxation time $\tau_1\propto1/T$ at the rest of the Fermi surface ($T$ is temperature). In qualitative agreement with the experiment, we find that Kohler's rule is strongly violated, but the ratio $\Delta\rho_{xx}/\rho_{xx}\tan^2\theta_H$, where $\tan\theta_H$ is the Hall angle, is approximately temperature-independent. We find the ratio is about 5.5, which is of the same order of magnitude as in the experiment.