  We report a concept of thermoelectric devices, cooperative spin caloritronics
device (CSCD), where cooperation between two or more energy channels such as
spin, charge and heat currents can significantly enhance energy efficiency of
spin caloritronic devices. We derive the figure of merit and the maximum
efficiency due to cooperative effect in analytic forms for a CSCD. Cooperative
effects significantly improve the figure of merit and the maximum efficiency in
spin caloritronic systems with multiply couplings effects. Several examples of
CSCDs, including electrical and thermal current induced DW motion,
spin-thermoelectric power generator and spin-thermoelectric cooling/heating,
are studied to illustrate the usefulness of the cooperative effect. We compare
the efficiency of CSCD with several recently proposed spin caloritronic
devices. Our scheme provides a novel route to seek high performance materials
and structures for future spin caloritronic devices.
