The "failed Kondo insulator" CeNiSn has long been suspected to be a nodal metal, with a node in the hybridization matrix elements. Here we carry out a series of Nernst effect experiments to delineate whether the severely anisotropic magnetotransport coefficients do indeed derive from a nodal metal or can simply be explained by a highly anisotropic Fermi surface. Our experiments reveal that despite an almost 20-fold anisotropy in the Hall conductivity, the large Nernst signal is isotropic. Taken in conjunction with the magnetotransport anisotropy, these results provide strong support for an isotropic Fermi surface with a large anisotropy in quasiparticle mass derived from a nodal hybridization.
@article{arxiv.1603.01258,
title = {Giant isotropic Nernst effect in an anisotropic Kondo semimetal},
author = {Ulrike Stockert and Peije Sun and Niels Oeschler and Frank Steglich and Toshiro Takabatake and Piers Coleman and Silke Paschen},
journal= {arXiv preprint arXiv:1603.01258},
year = {2016}
}