Under a thermal drive such as temperature gradient or chemical potential gradient, spin-up and spin-down carriers can flow perpendicularly to the thermal current and towards opposite directions without the application of a magnetic field.
The spin Nernst effect of electrons was first experimentally observed in 2016 and published by two independent groups in 2017.
In 2017, around the same time when its electronic counterpart was experimentally observed, the spin Nernst effect of magnons was first claimed in transition metal trichalcogenide MnPS3.
[5] However, the experiment involved ambiguities that cannot convincingly verify the spin Nernst effect of magnons, awaiting further experimental studies.
[6] At present, optical detection of the spin Nernst effect of magnons has not been reported.