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The metallic properties of high-temperature superconductors still represent a major unresolved issue. Fermi-liquid based interpretative approaches require the existence of a single quasiparticle scattering rate with an in-plane anisotropy that is temperature dependent [1]. Here we model the temperature dependence of resistivity ρ, Hall coefficient R_H and magnetoresistance MR in the heavily overdoped non-superconducting cuprate La1.7Sr0.3CuO4 using the so-called Ong representation [2]. Empirically, ρ ~ T2 up to 50K, MR ~ T-4 while R_H shows a strong temperature dependence, changing sign and becoming negative above T ≈ 170K.The positive Hall coefficient at low temperatures appears inconsistent with the electron-like Fermi surface reported by ARPES measurements at this doping. By introducing a Fermi surface with large regions of negative curvature centred on the zone-diagonals and an anisotropic and temperature dependent scattering path length we manage to achieve a satisfactory explanation and fitting of the experimental results. Our analysis implies a striking breakdown of the isotropic-l approximation at low temperatures in this heavily overdoped cuprate, a result that may have important implications for our understanding of the low-T Hall coefficient across the entire phase diagram [3]. [1] N.E.Hussey, Treatise on High Temperature Superconductivity, Ed. J.R. Schrieffer, (Springer Verlag, Amsterdam, 2006); [2] N.P.Ong, Phys. Rev. B 43, 193, (1991); [3] http://arxiv.org/abs/0707.4601. |
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