Magnetotransport properties of the topological nodal-line semimetal CaCdSn
Antu Laha, Sougata Mardanya, Bahadur Singh, Hsin Lin, Arun Bansil, Amit Agarwal, Z. Hossain
Abstract
Topological nodal-line semimetals support protected band crossings, which form nodal lines or nodal loops between the valence and conduction bands and exhibit novel transport phenomena. Here we address the topological state of the nodal-line semimetal candidate material CaCdSn, and report magnetotransport properties of its single crystals grown by the self-flux method. Our first-principles calculations show that the electronic structure of CaCdSn harbors a single nodal loop around the $\mathrm{\ensuremath{\Gamma}}$ point in the absence of spin-orbit coupling effects. The nodal crossings in CaCdSn are found to lie above the Fermi level and yield a Fermi surface that consists of both electron and hole pockets. CaCdSn exhibits high mobility ($\ensuremath{\mu}\ensuremath{\approx}3.44\ifmmode\times\else\texttimes\fi{}{10}^{4}\phantom{\rule{4pt}{0ex}}{\mathrm{cm}}^{2}{\mathrm{V}}^{\ensuremath{-}1}{\mathrm{s}}^{\ensuremath{-}1}$) and displays a field-induced metal-semiconductor-like crossover with a plateau in resistivity at low temperature. We observe an extremely large and quasilinear nonsaturating transverse as well as longitudinal magnetoresistance (MR) at low temperatures ($\ensuremath{\approx}7.44\ifmmode\times\else\texttimes\fi{}{10}^{3}%$ and $\ensuremath{\approx}1.71\ifmmode\times\else\texttimes\fi{}{10}^{3}%$, respectively, at 4 K). We also briefly discuss possible reasons behind such a large quasilinear magnetoresistance and its connection with the nontrivial band structure of CaCdSn.