The Hall effect can be extended by inducing a temperature gradient in lieu of electric field that is known as the Nernst (-Ettingshausen) effect. The recently discovered spin Nernst effect in heavy metals continues to enrich the picture of Nernst effect-related phenomena. However, the collection would not be complete without mentioning the valley degree of freedom benchmarked by the observation of the valley Hall effect. Here we show the experimental evidence of its missing counterpart, the valley Nernst effect. Using millimeter-sized WSe2 mono-multi-layers and the ferromagnetic resonance-spin pumping technique, we are able to apply a temperature gradient by off-centering the sample in the radio frequency cavity and address a single valley through spin-valley coupling. The combination of a temperature gradient and the valley polarization leads to the valley Nernst effect in WSe2 that we detect electrically at room temperature. The valley Nernst coefficient is in very good agreement with the predicted value.
@article{arxiv.1910.08070,
title = {The valley Nernst effect in WSe$_2$},
author = {Minh-Tuan Dau and Céline Vergnaud and Alain Marty and Cyrille Beigné and Serge Gambarelli and Vincent Maurel and Timothée Journot and Bérangère Hyot and Thomas Guillet and Benjamin Grévin and Hanako Okuno and Matthieu Jamet},
journal= {arXiv preprint arXiv:1910.08070},
year = {2020}
}