Enhanced spin Seebeck effect in the paramagnetic phase of the three-dimensional Heisenberg antiferromagnet RbMnF3

The spin Seebeck effect (SSE) consists of the generation of a spin current in a magnetic material under a thermal gradient, detected by the electric current it produces in an attached metallic layer. Here, the authors report studies of the SSE in RbMnF${}_{3}$, a nearly isotropic, insulating antiferromagnet with a N\'eel temperature of 83 K. By varying the applied magnetic field, they observe the antisymmetric step variation typical of the SSE, both in the ordered and paramagnetic phases, even at room temperature.