Dresden 2014 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 55: Poster II
MA 55.52: Poster
Freitag, 4. April 2014, 10:30–13:30, P2
Orphan Spin Glassiness — •J. Rehn1, A. Andreanov1, K. Damle2, A. Scardicchio3, A. Sen2, and R. Moessner1 — 1MPIPKS, Dresden — 2TIFR, Mumbai — 3ICTP, Trieste
Geometrically frustrated systems having a Coulomb phase, i.e., a system with a macroscopically degenerate ground state with power law decaying correlations, exhibit interesting low temperature excitations, e.g., in spin ice effectively described by interacting magnetic monopoles, which are created once the ice rules constraints are violated.
The consideration of disorder in systems with a Coulomb phase, such as the effects of dilution of non-magnetic impurities in the composite SCGO, leads to a similar effective picture: the ice rules constraints are violated because a ``Orphan Spin'' is left alone with non-magnetic impurities as neighbours.
An effective low temperature theory for such system describes the interactions among the Orphan Spins in terms of the correlations in the ground state of the pure system. In this project we show that the effective interactions of Orphan Spins on the checkerboard lattice must be of logarithmic form, if the temperatures are low enough. Monte Carlo simulations have been carried on to investigate the possibility of a spin glass phase. The main numerical results supporting the presence of a spin glass phase transition in this system are shown.