Department of Applied Mathematics, Faculty of Mechanical Engineering, Technical University, Letná 9, 042 00 Košice, Slovak Republic.
J Phys Condens Matter. 2011 May 4;23(17):175602. doi: 10.1088/0953-8984/23/17/175602. Epub 2011 Apr 15.
A hybrid lattice-statistical model on doubly decorated planar lattices, which have localized Ising spins at their nodal lattice sites and two itinerant electrons at each pair of decorating sites, is examined within the framework of an exact analytical method based on the generalized decoration-iteration mapping transformation. A particular emphasis is laid on the investigation of the effect of the on-site interaction U on the ground-state properties and critical behaviour of the system. It is shown that the ground state of the investigated hybrid system consists of a remarkable four-sublattice quantum antiferromagnetic phase, which manifests itself through a non-trivial criticality at non-zero temperatures. Moreover, the thermal variations of the staggered magnetization and the specific heat provide unambiguous evidence that the investigated spin-electron system exhibits the critical behaviour from the standard Ising universality class.
在基于广义修饰迭代映射变换的精确分析方法的框架内，研究了具有局域ising 自旋在节点格点和每对修饰格点上的两个巡游电子的双重修饰平面格上的混合晶格统计模型。特别强调了局域相互作用 U 对系统基态性质和临界行为的影响。结果表明，所研究的混合系统的基态由一个显著的四亚晶格量子反铁磁相组成，它通过在非零温度下的非平凡临界性表现出来。此外，交错磁化强度和比热的热变化提供了明确的证据，表明所研究的自旋电子系统表现出标准ising 普遍性类别的临界行为。
