Mechanism for lifting the degeneracy in the double-exchange spin ice model on a kagomé lattice: Dodecamer formation
arXiv:cond-mat/0504472 · doi:10.1016/j.physb.2005.01.374
Abstract
We investigated the double-exchange spin ice model on a kagomé lattice by Monte Carlo simulation in order to study a mechanism for lifting the degeneracy in frustrated electron systems. We show specific heat and vector spin chirality data on a finite lattice. Specific heat has a double-peak structure: A broad peak and a sharp peak are at $k_{\rm B}T/t \sim 0.15$ and 0.015, respectively, where $t$ is the transfer integral of electrons. The broad peak corresponds to a crossover to the spin ice-like state, on the other hand, the sharp one a transition to a dodecagonal spin cluster (dodecamer) state. We discuss the interplay between the formation of the dodecamer state and the lifting of the macroscopic degeneracy.
3 pages, 2 figures, to be published in Physica B (as the proceedings of SCES'04)