Spin-current State in Anisotropic Triangular Heisenberg Model

Stability of a spin-current state with respect to the ordinary magnetically disordered (paramagnetic) state is studied for an S=1/2 Heisenberg (J1-J2) model on an anisotropic triangular lattice in a magnetic field as a low-lying excited state as well as the ground state. We use a variational Monte Carlo method in computing expectation values. As a result, the spin-current state has an appreciably lower energy than that of the paramagnetic state for J1∼J2 (nearly isotropic) and 0.5 m 0.8 (m: magnetization), but in other areas, the energy gain is small if any, in contrast to a previous argument of Chubukov and Starykh for m ∼1/3.