Quantum Antiferromagnet at Finite Temperature: A Gauge Field Approach

Abstract

Starting from the $C{P}^{N-1}$ model description of the thermally disordred 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 supresses the one-particle motion, but enhances the staggered static susceptibility. This means that actual excitations in the system are represented by the collective spin-1 excitations, whereas 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.

REVTEX 3.0, 6 pages, TCSUH 93:085, 3 figures are available upon request from [email protected]

References in corpus (2)

• Universal quantum critical dynamics of two-dimensional antiferromagnets
• Large N expansion for frustrated and doped quantum antiferromagnets

Cited by in corpus (3)

• Dynamical structure factor of the triangular antiferromagnet: the Schwinger boson theory beyond the mean field approach
• RVB signatures in the spin dynamics of the square-lattice Heisenberg antiferromagnet
• Multimagnon and multispinon $L_3$-edge RIXS spectra of an effective ${\tilde{J}}_1-{\tilde{J}}_2-{\tilde{J}}_3$ square lattice Heisenberg model