Quantum destruction of spiral order in two-dimensional frustrated magnets

Article

关键词: PHASE-TRANSITIONS;    HEISENBERG ANTIFERROMAGNETS;    ISING-MODELS;    GAUGE-THEORY;    FIELD-THEORY;    LATTICE;    DUALITY;   

DOI  :  10.1103/PhysRevB.84.104430

来源: SCIE

【 摘 要 】

We study the fate of spin-1/2 spiral-ordered two-dimensional quantum antiferromagnets that are disordered by quantum fluctuations. A crucial role is played by the topological point defects of the spiral phase, which are known to have a Z(2) character. Previous works established that a nontrivial quantum spin-liquid phase results when the spiral is disordered without proliferating the Z(2) vortices. Here, we show that when the spiral is disordered by proliferating and condensing these vortices, valence-bond solid ordering occurs due to quantum Berry phase effects. We develop a general theory for this latter phase transition and apply it to a lattice model. This transition potentially provides a new example of a Landau-forbidden deconfined quantum critical point.

【 授权许可】

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