### Session B33: Cooperative Phenomena Theory

11:15 AM–2:15 PM, Monday, March 15, 2010
Room: E143

Chair: Chia-Ren Hu, Texas A&M University

Abstract ID: BAPS.2010.MAR.B33.2

### Abstract: B33.00002 : Infinite randomness and quantum'' Griffiths effects in a classical system: the randomly layered Heisenberg magnet

11:27 AM–11:39 AM

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#### Authors:

Priyanka Mohan
(Department of Physics, Indian Institute of Technology Madras)

Rajesh Narayanan
(Department of Physics, Indian Institute of Technology Madras)

Thomas Vojta
(Missouri University of Science and Technology)

We investigate the phase transition in a three-dimensional classical Heisenberg magnet with planar defects, i.e., disorder perfectly correlated in two dimensions. By applying a strong-disorder renormalization group, we show that the critical point has exotic infinite-randomness character. It is accompanied by strong power-law Griffiths singularities. We compute various thermodynamic observables paying particular attention to finite-size effects relevant for an experimental verification of our theory. We also study the critical dynamics within a Langevin equation approach and find it extremely slow. At the critical point, the autocorrelation function decays only logarithmically with time while it follows a nonuniversal power-law in the Griffiths phase.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2010.MAR.B33.2