2024/03/27 by Vivek Pandey, Pandey, Vivek, Sudhir K. Pandey +1
Materials Science · Physics and Astronomy · #2D Materials and Applications #FOS: Physical sciences #Graphene research and applications #Strongly Correlated Electrons (cond-mat.str-el) #Topological Materials and Phenomena
paper · pdf · doi:10.48550/arxiv.2403.18169
openalex publication_date 2024/03/27 · openalex created_date 2024/03/30 · openalex updated_date 2026/07/28
This work verifies the existence of dispersive nodal-arcs and their evolution into Weyl nodes under the effect of spin-orbit coupling (SOC) in NbAs & NbP. The obtained features mimic the observations as reported for TaAs & TaP in our previous work. In addition, this work reports that the number of nodes in TaAs class of Weyl semimetals (WSMs) can be altered via creating strain along a or c direction of the crystal. For instance, the number of nodes in NbAs under SOC-effect along with 2% (3%) tensile-strain in a direction is found to be 40 (56) in its full Brillouin zone (BZ). Besides the nodes, such strain are found to have considerable impact on the nodal-lines of these WSMs when effect of SOC is ignored. A 3% tensile (compressive) strain along the a (c) direction leads to the partially merging of nodal-lines (without SOC) in the extended BZ of NbAs & NbP, which is not observed in TaAs & TaP within the range of -3% to 3% strain. Apart from this, the work discusses the role of Weyl physics in affecting the Seebeck coefficient (S) of any WSM. In this direction, it is discussed that how a symmetric Weyl cone, even if tilted, will have no contribution to the S of WSMs. Furthermore, the work highlights the conditions under which a Weyl cone can contribute to the S of a given WSM. Lastly, the discussion of Weyl contribution to S is validated over TaAs class of WSMs via investigating the features of their Weyl cones and calculating the contributions of such cones to the S of these semimetals. The value of S contributed from Weyl cone is found to be as large as ∼65 μV/K below 25 K in case of TaAs. The findings of this work present a possibility of engineering the topological properties of TaAs class of WSMs via creating strain in their crystal. It also makes the picture of Weyl physics impact on the S of WSMs a more clear.