Longitudinal spin Seebeck effect in pyrochlore iridates with bulk and interfacial Dzyaloshinskii-Moriya interaction
The longitudinal spin-Seebeck eﬀect (SSE) in magnetic insulator|non-magnetic metal heterostruc- tures has been theoretically studied primarily with the assumption of an isotropic interfacial ex- change coupling. Here, we present a general theory of the SSE in the case of an antisymmetric Dzyaloshinskii-Moriya interaction (DMI) at the interface, in addition to the usual Heisenberg form. We numerically evaluate the dependence of the spin current on the temperature and bulk DMI using a pyrochlore iridate as a model insulator with all-in all-out (AIAO) ground state conﬁguration. We also compare the results of diﬀerent crystalline surfaces arising from diﬀerent crystalline orientations and conclude that the relative angles between the interfacial moments and Dzyaloshinskii-Moriya vectors play a signiﬁcant role in the spin transfer. Our work extends the theory of the SSE by includ- ing the anisotropic nature of the interfacial Dzyaloshinskii-Moriya exchange interaction in magnetic insulator|non-magnetic metal heterostructures and can suggest possible materials to optimize the interfacial spin transfer in spintronic devices.