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N. Barišić - Service de Physique de l’Etat Condensé, CEA-DSM-IRAMIS, Gif-sur-Yvette

Normal State of High-Tc Cuprates


Strong correlations among electrons in high-temperature superconducting cuprates give rise to a Mott AF-insulating parent state, from which superconductivity and, eventually, a Fermi-liquid-like metal emerge upon doping. At intermediate hole concentrations (p), the peculiar high-temperature metallic phase features a robust planar resistivity, linear in T (r µ T), and the deviation from this behavior upon cooling marks the opening of a partial gap (pseudogap) on some parts of the Fermi surface. Contrary to conventional wisdom, we find that the planar resistivity in the pseudogap phase of structurally simple HgBa2CuO4+δ (1) exhibits a quadratic T dependence (r µ T2), as in conventional Fermi liquids. By combining our results with prior work, we arrive at a novel phase diagram containing four characteristic temperatures (Tc < T ’ < T** < T*). T* is coincident with the onset of novel q = 0 magnetic order revealed by neutron diffraction (2). T** denotes a second, somewhat lower pseudogap temperature that we tentatively associate to a separate magnetic transition ; T ’, which marks the onset of superconducting fluctuations (3,4). Notably, T ’ determined from microwave conductivity measurements lies only 10-20 K above Tc and closely tracks the superconducting dome with doping. By defining the resistivity per copper-oxygen plaquette, which is a building block of cuprates, we have determined the universal resistivity in both the linear and quadratic regimes. We further suggest that scattering rates associated with r µ T2 and r µ T do not change throughout the entire accessible doping range (0.01 < p < 0.35).

 

1. N. Barišić, Y. Li, X. Zhao, Y. Cho, G. Chabot-Couture, G. Yu, M. Greven. Phys. Rev. B 78, 054518 (2008).

2. Y. Li, V. Baledént, N. Barišić, Y. Cho, B. Fauque, Y. Sidis, G. Yu, X. Zhao, P. Bourges, M. Greven. Nature 455, 372 (2008).

3. M. S. Grbić, N. Barišić, A. Dulčić, I. Kupčić, Y. Li, X. Zhao, M. Dressel, M . Greven, M. Požek. Phys. Rev. B 80, 094511 (2009).

4. M. S. Grbić, M. Požek, D. Paar, V. Hinkov, M. Raichle, D. Haug, B. Keimer, N. Barišić, A. Dulčić.Phys. Rev. B 83, 144508 (2011).