QUANTUM ANTIFERROMAGNET AT FINITE-TEMPERATURE - A GAUGE-FIELD APPROACH

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关键词: SPIN DYNAMICS;    GROUND-STATES;    VALENCE-BOND;    PEIERLS;   

DOI  :  10.1103/PhysRevB.49.4368

来源: SCIE

【 摘 要 】

Starting from the CP(N-1) model description of the thermally disordered phase of the D = 2 quantum antiferromagnet, we examine the interaction of the Schwinger-boson spin-1/2 mean-field excitations with the generated gauge (chirality) fluctuations in the framework of the 1/N expansion. This interaction dramatically suppresses the one-particle motion, but enhances the staggered static susceptibility. This means that the actual excitations in the system are represented by the collective spin-I excitations, whereas the one-particle excitations disappear from the problem. We also show that massive fluctuations of the constraint field are significant for the susceptibility calculations. A connection with the problem of a particle in random magnetic field is discussed.

【 授权许可】

Free