The giant planar Hall effect and anisotropic magnetoresistance in Dirac node arcs semimetal PtSn₄

Topological semimetals (TSMs) present intriguing quantum states and have attracted much attention in recent years because of exhibiting various anomalous magneto-transport phenomena. Theoretical prediction shows that some novel phenomena, such as negative magnetoresistance (MR) and the planar Hall effect (PHE), originate from the chiral anomaly in TSMs. In this work, high-field (33 T) Shubnikov-de Haas (SdH) oscillations are obtained to reveal the topology of PtSn₄. Giant PHE and anisotropic magnetoresistance (AMR) are observed in Dirac node arcs of semimetal PtSn₄. First, a non-zero transverse voltage can be acquired while tilting the in-plane magnetic field. Moreover, the amplitude of PHE sharply increases atT^*∼ 50 K with decreasing temperature, which is suggested to be related to the Fermi surface reconstruction observed in PtSn₄. Subsequently, the field-dependent amplitudes of the PHE show an abnormal behavior around 50 K, which is thought to stem from the complex correlation between the chiral charge and electric one in PtSn₄driving the system into different coupling states due to the complicated band structure. On the other hand, the relative AMR is negative and up to -98% at 8.5 T. Our work proves that the PHE measurements are a convincing transport fingerprint feature to confirm the chiral anomaly in TSMs.