Magnetic clustering at a quantum critical point: A modified percolation theory

ORAL

Abstract

The formation and dynamics of magnetic clusters have proven to be important for materials that have been driven to a quantum critical point via substantial chemical substitution. Tiny variations in the local exchange interaction lead to the formation of a distribution of Kondo temperatures, which in turn gives rise to a fragmentation of the magnetic lattice. Importantly, the temperature scale at which the clusters form is typically low enough that finite-size effects force the clusters to order internally as soon as they form. We argue that this process defies description by a standard percolation model but that a slight restriction-- whereby ordered clusters are not allowed to be broken up-- succeeds, but with the consequence that a new universality class emerges. We demonstrate this model with analytics as well as Monte-Carlo numerical results.

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Authors

  • John Gaddy

    University of Missouri, Department of Physics and Astronomy

  • John Gaddy

    University of Southern California, University of Chicago, University of Toronto, Argonne National Laboratory, Illinois Institute of Technology, University of Northern Iowa, Universite Aix-Marseille 1, Universite Montpellier 2, University of Missouri, University of Missouri, Department of Physics and Astronomy and the Missouri Research Reactor, University of Missouri, Department of Physics and Astronomy, University of Missouri, the Missouri Research Reactor, Columbia Univ, Univ of Northern Iowa, University of Charleston, NASA Goddard Space Flight Center, Iowa State University, University of Colorado, NOAO, University of Toledo, University of Massachusetts, Smith College, Observatory of Bordeaux, Spitzer Science Center, University of Chile, SAO

  • John Gaddy

    University of Southern California, University of Chicago, University of Toronto, Argonne National Laboratory, Illinois Institute of Technology, University of Northern Iowa, Universite Aix-Marseille 1, Universite Montpellier 2, University of Missouri, University of Missouri, Department of Physics and Astronomy and the Missouri Research Reactor, University of Missouri, Department of Physics and Astronomy, University of Missouri, the Missouri Research Reactor, Columbia Univ, Univ of Northern Iowa, University of Charleston, NASA Goddard Space Flight Center, Iowa State University, University of Colorado, NOAO, University of Toledo, University of Massachusetts, Smith College, Observatory of Bordeaux, Spitzer Science Center, University of Chile, SAO

  • John Gaddy

    University of Southern California, University of Chicago, University of Toronto, Argonne National Laboratory, Illinois Institute of Technology, University of Northern Iowa, Universite Aix-Marseille 1, Universite Montpellier 2, University of Missouri, University of Missouri, Department of Physics and Astronomy and the Missouri Research Reactor, University of Missouri, Department of Physics and Astronomy, University of Missouri, the Missouri Research Reactor, Columbia Univ, Univ of Northern Iowa, University of Charleston, NASA Goddard Space Flight Center, Iowa State University, University of Colorado, NOAO, University of Toledo, University of Massachusetts, Smith College, Observatory of Bordeaux, Spitzer Science Center, University of Chile, SAO