Six-sublattice structure of the multiple-spin exchange model on the triangular lattice in the magnetic field

Abstract We study the spin- 1 2 multiple-spin exchange model with two-, three- and four-spin cyclic exchange interactions on a triangular lattice in a magnetic field. This model is believed to describe the nuclear magnetism of solid He 3 layers. In our previous study, the spin-wave analysis showed that the Y-shape ground state survives quantum fluctuations and softening of the spin wave leads a second-order phase transition to a six-sublattice phase. In the present work, we specified the novel non-coplanar spin structure of the six-sublattice phase within the mean-field approximation and estimated the uniform vector chiral order and the staggered scalar chiral order parameters.