Spin current and spiral spinons in the Heisenberg spin chain

The twisted boundary magnetic field effects on the one dimensional antiferromagnetic spin chains with spin half and spin one are studied via the density matrix renormalization group method. A spin voltage controlled by the twisted boundary fields as well as the spin current are observed for the spin half chain. The correlation functions reveal the spiral nature of spin structure for both ground state and the spinon excitations for the spin half case. For the spin one chain, a kink is generated in the ground state and the midgap state is induced by small boundary fields.