Evidence for Spin Swapping in an Antiferromagnet
In the past decades, climate change and an energy crisis have prompted researchers to focus on improving the efficiency of power-saving and energy conversion devices. Thermoelectric generation is a key materials-based idea with great potential in applications.
J. Zhou (U. Texas-Austin); G. Fiete (Northeastern U.); C.L. Chien (Johns Hopkins U.)
In the past decades, climate change and an energy crisis have prompted researchers to focus on improving the efficiency of power-saving and energy conversion devices. Thermoelectric generation is a key materials-based idea with great potential in applications.
Spin caloritronics is an emerging field with great potential for building a new type thermoelectric device with an efficiency exceeding the limit imposed by a single material in conventional thermoelectric devices. As a key phenomena of spin caloritronic devices, a voltage induce via a temperature gradient parallel to the interface, as shown in the figure on the right, has been missing.
We have demonstrated the desired response in the canted spin antiferromagnet LaFeO3 with the coating of heavy metals of Pt and W, and provided a thorough investigation of the vector spin Seebeck effect associated with the antiferromagnet. Remarkably, the thermal voltage generated via the parallel temperature gradient in LaFeO3 is comparable to the longitudinal spin Seebeck effect (perpendicular temperature gradient) found in the well studied Y3Fe5O12(YIG)/Pt system. The unique response in LaFeO3/Pt can be accounted for by a spin swapping model proposed by the team in the citation below.