Anab initio study of topological and transport properties of YAuPb

Abstract

In the last few decades, the study of topological materials has been carried out on an extensive scale. Half-Heusler alloys are well known for their topological behaviours. In this work, we present a detailed study of topological properties of a ternary half-Heusler alloy, YAuPb, using the tight-binding approach. We have calculated some important topological properties which includes-finding nodes and their chiralities, Berry curvature (Ω) and the surface-states. Five pairs of characteristic nodes with equal and opposite chiralities are obtained. Based on the study of these properties, we categorise the material as non-trivial topological semimetal. Besides the topological behaviours, we present a comparative study of temperature dependent transport properties corresponding to the chemical potential (μ) of the Fermi level and the node points. The temperature range chosen for the study is 50-300 K. The results obtained from the calculations of electrical conductivity per unit relaxation time (σ/τ ) and the electronic part of thermal conductivity per unit relaxation time (κ 0 ) indicates the conducting nature of the material to both the heat and electricity. At the Fermi level, the value of Seebeck coefficient (S) is found to be ∼ −9.07 (−35.95) μV K −1 at 50(300) K. The negative value of S indicates the n-type behaviour of the compound. The calculated value of electronic specific heat (Pauli magnetic susceptibility) corresponding to Fermi level is ∼ 0.03(0.18) × 10 −2 J mol −1 K −1 (∼ 1.21(1.14) × 10 −10 m 3 mol −1 ) at 50(300) K. This work suggests that YAuPb is a promising candidate of non-trivial topological semimetals which can be employed in transmission of heat and electricity, and as n-type material within the temperature range of 50-300 K.

PY-Nodes: An ab-initio python code for searching nodes in a material using Nelder-Mead's simplex approach

“…al. have extensively investigated the nodes in YAuPb using the tight-binding approach 26 . In their study, only 10 nodes were obtained.…”

“…The material has been already claimed to be topological semimetal 34 . Furthermore, the semimetallic properties of the compound have already been extensively investigated 26 . In this work, it has been found that the compound shows several signatures of semimetals such as (i) existence of node points with specific chiralities, (ii) berry-curvature associated with these nodes, and (iii) observation of surface states.…”

Existence of nodal-arc and its evolution into Weyl-nodes in the presence of spin-orbit coupling in TaAs & TaP

“…Topological bands-crossings near the Fermi level are of great importance in present condensed-matter physics research. The popular classes of materials associated with such bands-degeneracy includes-Weyl semimetals (WSMs) [1][2][3][4], Dirac-semimetals (DSMs) [5][6][7] and nodal-line semimetals (NLSMs) [8][9][10]. The WSMs contain discrete set of two-fold bands-intersections between conduction and valence bands across their full Brillouin zone (BZ).…”

Corrigendum: An ab initio study of topological and transport properties of YAuPb (2021 J. Phys.: Condens. Matter 33 475503)

“…This corrigendum to the original article [1] represents the correction in figure 1(a) and the modification of the corresponding lines in the manuscript.…”