Ha. Ceccatto et al., NONCLASSICAL DISORDERED PHASE IN THE STRONG QUANTUM LIMIT OF FRUSTRATED ANTIFERROMAGNETS, Physical review. B, Condensed matter, 47(18), 1993, pp. 12329-12332
The rotationally invariant Schwinger-boson approach to quantum helimag
nets is discussed. It is shown that in order to get quantitative agree
ment with exact results on finite lattices, parity-breaking pairing of
bosons must be allowed. For the J1-J2-J3 model on the special line J2
= 2J3, a quantum disordered phase is found, though notably only in th
e strong quantum limit S = 1/2. The theory predicts the direct melting
of biaxial helimagnetic order into an isotropic spin fluid, without t
he formation of an intermediate spin-nematic phase as recently suggest
ed.