Magnetotransport and electronic structure of the antiferromagnetic semimetal YbAs

Abstract

A number of rare-earth monopnictides have topologically non-trivial band structures together with magnetism and strong electronic correlations. In order to examine whether the antiferromagnetic (AFM) semimetal YbAs (TN = 0.5 K) exhibits such a scenario, we have grown high-quality single crystals using a flux method, and characterized the magnetic properties and electronic structure using specific heat, magnetotransport and angle-resolved photoemission spectroscopy (ARPES) measurements, together with density functional theory (DFT) calculations. Both ARPES and DFT calculations find no evidence for band inversions in YbAs, indicating a topologically trivial electronic structure. From low-temperature magnetotransport measurements, we map the field-temperature phase diagram, where we find the presence of a field stabilized phase distinct from the AFM phase at low temperatures. An extremely large magnetoresistance (XMR) for both YbAs and the nonmagnetic counterpart LuAs, is also observed, which can consistently be accounted for by the presence of electron-hole compensation. Moreover, an angle-dependent study of the Shubnikov-de Haas effect oscillations reveals very similar Fermi surfaces between YbAs and LuAs, with light effective masses down to at least 0.5 K, indicating that the Yb-4f electrons are well localized, and do not contribute to the Fermi surface. However, the influence of the localized Yb-4f electrons on the magnetotransport of YbAs can be discerned from the distinct temperature dependence of the XMR compared to that of LuAs, which we attribute to the influence of short-ranged spin correlations onsetting well above TN.

Semimetallic Kondo lattice behavior in YbPdAs with a distorted kagome structure

“…The volume of the Fermi pockets is relatively small, which is consistent with the low carrier concentration, according to Luttinger's theorem [49]. The carrier densities for electrons and holes are calculated to be 7.39 × 10 20 and 7.82 × 10 20 cm −3 , respectively, which are moderately small, comparable to those of semimetallic YbAs [27]. However, a small carrier density is not likely the origin of the increase of resistivity upon cooling at intermediate temperatures, since purely metallic behavior is found in LuPdAs, which has similarly small Fermi surfaces.…”

“…The quartz ampule was slowly heated up to 900 • C, kept there for three days before being furnace-cooled down to room temperature. The formation of the much more stable YbAs phase appears to hinder the growth of YbPdAs single crystals [27].…”

Temperature-dependent Fermi surface probed by Shubnikov–de Haas oscillations in topological semimetal candidates DyBi and HoBi

“…For DyBi, our observation of the SdH oscillations is the first, and the frequencies we obtained (see Table 1 ) are quite close to those found for HoBi, which implies that relevant sheets of Fermi surfaces in both compounds are rather similar. According to the results of several theoretical calculations, Fermi surfaces of REPn compounds, which contain heavy rare earth elements, are qualitatively similar, all of them possess two or three nearly isotropic hole-like pockets in the center of the Brillouin zone and strongly anisotropic triplicate electron-like pocket 8 , 16 , 25 – 27 , 34 , 59 – 61 . In the magnetic-field induced polarized state (with all spins aligned with strong enough magnetic field) the electronic structure of magnetic REPn changes with each Fermi pocket splitting into two pockets due to the magnetic-field induced time-reversal symmetry breaking 25 , 27 , 33 , 34 .…”