Order-disorder phase transitions in magnetic metals that occur at zero temperature have been studied in great detail. Theorists have advanced scenarios for these quantum critical systems in which the unusual response can be seen to evolve from a competition between ordering and disordering tendencies, driven by quantum fluctuations. Unfortunately, there is a potential disconnect between the real systems that are being studied experimentally, and the idealized systems that theoretical scenarios are based upon. Here we discuss how disorder introduces a change in morphology from a three-dimensional system to a collection of magnetic clusters, and we present neutron scattering data on a classical system, Li[Mn1.96Li0.04]O4, that show how magnetic clusters by themselves can lead to scaling laws that mimic those observed in quantum critical systems.
J. Lamsal et al., "The Search for Quantum Critical Scaling in a Classical System," Journal of Applied Physics, American Institute of Physics (AIP), Jan 2009.
The definitive version is available at http://dx.doi.org/10.1063/1.3068409
United States. Department of Energy
University of Missouri Research Board
Keywords and Phrases
Fluctuations; Lithium Compounds; Magetic Structure; Magnetic Transitions; Neutron Diffraction; Order-Disorder Transformations
Article - Journal
© 2009 American Institute of Physics (AIP), All rights reserved.