Eleanor Scott1,Poulomi Chakraborty2,Satya Guin3,4,Brian Skinner2,Sarah J. Watzman1
University of Cincinnati1,The Ohio State University2,Max Planck Institute for Chemcial Physics of Solids3,Birla Institute of Technology anf Science4
Eleanor Scott1,Poulomi Chakraborty2,Satya Guin3,4,Brian Skinner2,Sarah J. Watzman1
University of Cincinnati1,The Ohio State University2,Max Planck Institute for Chemcial Physics of Solids3,Birla Institute of Technology anf Science4
The topological and semimetallic effects of Weyl semimetals make them excellent candidates for magneto-thermoelectric transport. Previous work in the thermoelectric properties of Type I Weyl semimetals (WSMs) has found that this class of materials possess both a large magneto-Seebeck effect and Nernst effect simultaneously, is very sensitive to doping, and that magneto-thermoelectric effects are maximized when the temperature is comparable to the Fermi energy. [1, 2]. Here, we shift our focus to Type II WSMs, which possesses asymmetric Dirac bands, unlike the band symmetry assumed in Type I WSMs. Our candidate material is WTe<sub>2</sub>, and previous single-crystalline data observed an extremely large Nernst thermopower, exceeding 7,000 uV K<sup>-1</sup> at 11.3 K and 9 T [3]. However, literature does not include full magneto-thermoelectric transport data over a broad temperature range, which we present here in polycrystalline WTe<sub>2</sub>. Experimental results indicate that unlike the behavior observed in the Type I WSM [1], the magneto-Seebeck effect is significantly reduced and is not maximized in the same temperature range as the Nernst effect. Additionally, the Nernst thermopower of this Type II WSM did not exhibit an anomalous Nernst effect beyond cryogenic temperatures, while NbP, a Type I WSM, exhibited anomalous behavior over a broad temperature range.<br/>Our experimental work is complemented by theoretical models of the thermoelectric transport behavior. Previous theoretical models created for the NbP work matched well with the transport behavior seen in the experimental results. This model is then altered to account for the tilted band structure and transport properties specific to WTe<sub>2</sub>. By comparing both the experimental and theoretical results of thermoelectric transport in NbP and WTe<sub>2</sub>, we can determine how the tilting of Dirac bands effects magneto-thermoelectric transport behavior in WSMs.<br/><br/>[1] E. F. Scott et al.<i> Phys. Rev. B</i> <b>107</b>, 115108 (2023)<br/>[2] S. J. Watzman et al. <i>Phys. Rev. B</i> <b>97</b>, 161404(R) (2018).<br/>[3] Y. Pan, et al. <i>Nat Commun</i> <b>13</b>, 3909 (2022).