Berlin 2008 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 34: Correlated Electrons: Metal-Insulator Transition 2

TT 34.17: Vortrag

Donnerstag, 28. Februar 2008, 18:30–18:45, H 2053

Frustrated metallicity in the quasi-one-dimensional metal PrBa₂Cu₄O₈ — •Alessandro Narduzzo^1,2, Araz Enayati-Rad¹, Florence Rullier-Albenque³, Shigeru Horii⁴, and Nigel E. Hussey¹ — ¹University of Bristol, UK; — ²IFW Dresden, Germany; — ³Saclay, Paris, France; — ⁴University of Tokyo, Japan.

We have investigated the metallic ground state of the extremely anisotropic quasi-one-dimensional metal PrBa₂Cu₄O₈ (t_b²: t_a²: t_c² ∼ 4000: 2: 1), the non-superconducting analogue of the high-T_c cuprate YBa₂Cu₄O₈, as a function of disorder content, introduced either through atomic-site substitution or electron irradiation [1, 2]. A common single disorder threshold is found to drive interchain and inchain resistivities into a low temperature regime where they display d ρ /dT<0. The survival of a large magnetoresistance of orbital origin reveals the itinerancy of the electronic system not to be suppressed by the presence of disorder [3]. We propose an interpretative scenario based on a microscopic electronic fragmentation of the metallic chains, though in contrast to many previous theoretical proposals, coherent hopping between chains appears to remain a relevant perturbation within the disordered system.

[1] New J. Phys. 8 (2006) 172-183; [2] Phys. Rev. Lett. vol. 99, 136402 (2007); [3] Phys. Rev. Lett. vol. 98, 146601 (2007).