Persistent spin current in mesoscopic antiferromagnet spin chain with Dzyaloshinskii-Moriya interaction

By using the modified spin-wave and gauge invariant methods, we show that at zero temperature in the presence of an inhomogeneous magnetic field with magnitude B gives rise to a persistent magnetization current around a mesoscopic antiferromagnetic Heisenberg spin ring with the DM (Dzyaloshinskii-Moriya) interaction. The results show that the persistent magnetization current is vanishing at large Ds/J (Ds is reduced DM interaction and J is nearest exchange coupling) with α>1 (α is a constant describing the energy gap of the spin system). The result also shows that under the homogeneous magnetic field there exists a non-zero spin current in the spin ring.