Berlin 2012 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 38: Correlated Electrons: Spin Systems and Itinerant Magnets 1
TT 38.7: Talk
Thursday, March 29, 2012, 11:00–11:15, H 3010
Low temperature thermal and electrical transport properties of ZrZn2 in high magnetic field — •Yang Zou1, Michael Sutherland1, Stephen Hayden2, Daniel Rothfuss3, Andreas Fleischmann3, Christian Enss3, and F. Malte Grosche1 — 1University of Cambridge, UK — 2University of Bristol, UK — 3Universität Heidelberg, Germany
Metals close to a ferromagnetic quantum critical point offer a comparatively clear and well-defined environment to investigate the breakdown of Landau’s Fermi liquid theory. The low temperature band ferromagnet ZrZn2 violates the predictions of Fermi liquid theory over a wide temperature range at low temperatures. Transport and heat capacity measurements suggest the presence of a marginal Fermi-liquid, predicted to occur close to a ferromagnetic quantum critical point by spin fluctuation theory [1]. In order to investigate the nature of the Fermi-liquid breakdown in this material, we have implemented electrical and thermal conductivity measurements down to temperatures of 100 mK and in high magnetic field. In zero field our measurements confirm the finding reported in [2] that, to leading order in temperature T, the electrical and effective thermal resistivities at low temperature take a T5/3 and T form, respectively. These are the signatures of the marginal Fermi-liquid. At very low temperatures and in finite magnetic field we find that the electrical resistivity assumes quadratic temperature dependence, consistent with a return to conventional Fermi-liquid behaviour.
Sutherland et al. ArXiv:1110.5240v1 [cond-mat.str-el].
Smith et al. Nature 455 7217 (2008).