Plaquette order in the J(1)-J(2)-J(3) model: Series expansion analysis

Article

关键词: QUANTUM HEISENBERG-ANTIFERROMAGNET;    PHASE-TRANSITIONS;    GROUND-STATES;    2 DIMENSIONS;    DIMER ORDER;    LATTICE;   

DOI  :  10.1103/PhysRevB.78.224415

来源: SCIE

【 摘 要 】

Series expansion based on the flow equation method is employed to study the zero-temperature properties of the spin-1/2 J(1)-J(2)-J(3) antiferromagnet in two dimensions. Starting from the exact limit of decoupled plaquettes in a particular generalized J(1)-J(2)-J(3) model, we analyze the evolution of the ground-state energy and the elementary triplet excitations in powers of all three interplaquette couplings up to fifth order. We find that the plaquette phase remains stable over a wide range of exchange couplings and connects adiabatically up to the case of the plain J(1)-J(2)-J(3) model but not to the J(1)-J(2) model at J(3)=0. Besides confirming the existence of such a phase, recently predicted by Mambrini [Phys. Rev. B 74, 144422 (2006)], we estimate its extent by Dlog-Pade analysis of the critical lines that result from closure of the triplet gap.

【 授权许可】

Free