Self-consistent perturbative evaluation of ground-state energies: Application to cohesive energies of spin lattices

Article

关键词: COUPLED-CLUSTER;    FINITE-SIZE;    HEISENBERG-ANTIFERROMAGNET;    QUANTUM ANTIFERROMAGNETS;    FERMION SYSTEMS;    PARAMETERS;    EXPANSION;    MODEL;    BEHAVIOR;   

DOI  :  10.1103/PhysRevB.70.184441

来源: SCIE

【 摘 要 】

This work presents a simple formalism which proposes an estimate of the ground-state energy from a single reference function. It is based on a perturbative expansion but leads to nonlinear coupled equations. It can be viewed as well as a modified coupled cluster formulation. Applied to a series of spin lattices governed by model Hamiltonians the method leads to simple analytic solutions. The so-calculated cohesive energies are surprisingly accurate. Two examples illustrate its applicability to locate phase transition.

【 授权许可】

Free