Ground state structure of random magnets

Journal Article · Thu Oct 01 00:00:00 EDT 1998 · Physical Review. E, Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics

DOI:https://doi.org/10.1103/PhysRevE.58.4261· OSTI ID:662212

Bastea, S; Duxbury, P M ^[1]

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1. Department of Physics Astronomy and Center for Fundamental Materials Research, Michigan State University, East Lansing, Michigan 48824-1116 (United States)

Using exact optimization methods, we find all of the ground states of ({plus_minus}h) random-field Ising magnets (RFIM) and of dilute antiferromagnets in a field (DAFF). The degenerate ground states are usually composed of isolated clusters (two-level systems) embedded in a frozen background. We calculate the paramagnetic response (sublattice response) and the ground state entropy for the RFIM (DAFF) due to these clusters. In both two and three dimensions there is a broad regime in which these quantities are strictly positive, even at irrational values of h/J (J is the exchange constant). {copyright} {ital 1998} {ital The American Physical Society}

• OSTI ID: 662212
• Journal Information: Physical Review. E, Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics, Vol. 58, Issue 4; Other Information: PBD: Oct 1998
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ANTIFERROMAGNETIC MATERIALS
ISING MODEL
MAGNETS
GROUND STATES
ANTIFERROMAGNETISM
OPTIMIZATION
STOCHASTIC PROCESSES
ENTROPY