Pseudogap behavior in charge density wave kagome material ScV6Sn6 revealed by magnetotransport measurements

Abstract

AbstractOver the last few years, significant attention has been devoted to studying the kagome materialsAV3Sb5(A = K, Rb, Cs) due to their unconventional superconductivity and charge density wave (CDW) ordering. Recently$${{{{\rm{ScV}}}}}_{6}{{{{\rm{Sn}}}}}_{6}$$ScV6Sn6was found to host a CDW below ≈ 90 K, and, likeAV3Sb5, it contains a kagome lattice comprised only of V ions. Here we present a comprehensive magnetotransport study on$${{{{\rm{ScV}}}}}_{6}{{{{\rm{Sn}}}}}_{6}$$ScV6Sn6. We discovered several anomalous transport phenomena above the CDW ordering temperature, including insulating behavior in interlayer resistivity, a strongly temperature-dependent Hall coefficient, and a violation of Kohler’s rule. All these anomalies can be consistently explained by a progressive decrease in carrier densities with decreasing temperature, suggesting the formation of a pseudogap. Our findings suggest that high-temperature CDW fluctuations play a significant role in determining the normal state electronic properties of$${{{{\rm{ScV}}}}}_{6}{{{{\rm{Sn}}}}}_{6}$$ScV6Sn6.