Enhanced electron correlations in the new binary stannide PdSn4: a homologue of the Dirac nodal arc semimetal PtSn4

Abstract

The advent of nodal-line semi-metals, i.e. systems in which the conduction and valence bands cross each other along a closed trajectory (line or loop) inside the Brillouin zone, has opened up a new arena for the exploration of topological condensed matter in which, due to a vanishing density of states near the Fermi level, electron correlation effects may also play an important role. In spite of this conceptual richness however, material realization of nodal-line (loop) fermions is rare, with PbTaSe2, ZrSiS and PtSn4 the only promising known candidates. Here we report the synthesis and physical properties of a new compound PdSn4 that is isostructural with PtSn4 yet possesses quasiparticles with significantly enhanced effective masses. In addition, PdSn4 displays an unusual polar angular magnetoresistance which at a certain field orientation, varies linearly with field up to 55 Tesla. Our study suggests that, in association with its homologue PtSn4 whose low-lying excitations were recently claimed to possess Dirac node arcs, PdSn4 may be a promising candidate in the search for novel topological states with enhanced correlation effects.