Orbital multicriticality in spin-gapped quasi-one-dimensional antiferromagnets

Article

关键词: 2-DIMENSIONAL ISING-MODEL;    FIELD-THEORY;    ANNNI MODEL;    LIQUID;    PHASE;   

DOI  :  10.1103/PhysRevB.84.014407

来源: SCIE

【 摘 要 】

Motivated by the quasi-one-dimensional antiferromagnet CaV2O4, we explore spin-orbital systems in which the spin modes are gapped but orbitals are near a macroscopically degenerate classical transition. Within a simplified model we show that gapless orbital liquid phases possessing power-law correlations may occur without the strict condition of a continuous orbital symmetry. For the model proposed for CaV2O4, we find that an orbital phase with coexisting order parameters emerges from a multicritical point. The effective orbital model consists of zigzag-coupled transverse field Ising chains. The corresponding global phase diagram is constructed using field theory methods and analyzed near the multicritical point with the aid of an exact solution of a zigzag XXZ model.

【 授权许可】

Free