Berlin 2008 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 33: Symposium: High-Temperature Superconductivity

TT 33.1: Hauptvortrag

Donnerstag, 28. Februar 2008, 14:00–14:30, H 0104

Transport Evidence for Quantum Criticality in Electron-doped Cuprates — •Richard Greene — University of Maryland, College Park, USA

Over the past few years, strong evidence for quantum critical behavior in electron-doped cuprates has been observed in transport [1], optical conductivity [2], ARPES [3], and neutron scattering [4] experiments. More recent work on Pr_2−xCe_xCuO₄ films, using high-field resistivity and Hall Effect up to 60 T [6], low temperature thermopower [5] in the normal state, and in-plane angular magnetoresistance (AMR) [7], are consistent with the view that a quantum phase transition occurs under the superconducting dome near x=0.16 doping. These measurements can be interpreted with a spin-density-wave induced reconstruction of the Fermi surface, which leads to both electron and hole-like pockets. In this talk, I will review some of this work and compare it to recent high-field transport experiments in hole-doped cuprates, where evidence of electron-like Fermi surface pockets has been found [8].

1) Dagan et al. PRL 92, 167001 (2004) ;

2) Zimmers et al. Europhys. Lett. 70, 225 (2005);

3) Matsui et al., PRB 75, 224514 (2007) and references therein;

4) Motoyama et al., Nature 445, 912 (2007) and references therein;

5) Li et al. PRB 75, 020506R (2007) ;

6) Li et al. PRL 99, 047003 (2007) ;

7) W. Yu et al. PRB 76, 020503R (2007) ;

8) LeBoeuf et al. Nature 450, 533 (2007)