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TT: Tiefe Temperaturen
TT 22: Quantenphasenüberg
änge
TT 22.2: Vortrag
Donnerstag, 29. März 2001, 12:00–12:15, J
Enhanced Altshuler-Aronov singularities and Marginal Fermi-Liquid Effects at a Quantum Critical Point — •Thomas Vojta1, Dietrich Belitz2, Theodore R. Kirkpatrick3, and Rajesh Narayanan4 — 1Institut für Physik, TU Chemnitz, 09107 Chemnitz — 2Department of Physics and Materials Science Institute, University of Oregon, Eugene, OR 97403, USA — 3Institute for Physical Science and Technology and Department of Physics, University of Maryland, College Park, MD 20742, USA — 4Theoretical Physics, University of Oxford, OX3 1NP, UK
The conductivity and the tunneling density of states of disordered itinerant electrons in the vicinity of a ferromagnetic transition at low temperature are discussed. Critical fluctuations lead to nonanalytic frequency and temperature dependences that are distinct from the usual long-time tail effects in a disordered Fermi liquid. The crossover between these two types of behavior is proposed as an experimental check of recent theories of the quantum ferromagnetic critical behavior. In addition, the quasiparticle properties at criticality are shown to be those of a marginal Fermi liquid.