Spin transport in the disordered phase of a frustrated antiferromagnet

I analyze the spin transport, in the disordered phase, of the frustrated Heisenberg antiferromagnet with spin S=1 with next and next-nearest neighbor interactions on a square lattice. The spin conductivity is calculated using a SU(3) Schwinger boson formalism and the Kubo theory, within the ladder approximation. The spin conductivity exhibits a nonzero Drude weight at finite temperature.