Fermi surface evolution of Na-doped PbTe studied through density functional theory calculations and Shubnikov-de Haas measurements

Abstract

We present a combined experimental and theoretical study of the evolution of the low-temperature Fermi surface of lead telluride, PbTe, when holes are introduced through sodium substitution on the lead site. Our Shubnikov-de-Haas measurements for samples with carrier concentrations up to $9.4\times 10^{19}$cm${}^{-3}$ (0.62 Na atomic $\%$) show the qualitative features of the Fermi surface evolution (topology and effective mass) predicted by our density functional (DFT) calculations within the generalized gradient approximation (GGA): we obtain perfect ellipsoidal L-pockets at low and intermediate carrier concentrations, evolution away from ideal ellipsoidicity for the highest doping studied, and cyclotron effective masses increasing monotonically with doping level, implying deviations from perfect parabolicity throughout the whole band. Our measurements show, however, that standard DFT calculations underestimate the energy difference between the L-point and $\Sigma$-line valence band maxima, since our data are consistent with occupation of a single Fermi surface pocket over the entire doping range studied, whereas the calculations predict an occupation of the $\Sigma$-pockets at higher doping. Our results for low and intermediate compositions are consistent with a non-parabolic Kane-model dispersion, in which the L-pockets are ellipsoids of fixed anisotropy throughout the band, but the effective masses depend strongly on Fermi energy.

17 pages, 18 figures

References in corpus (8)

• Restoring the density-gradient expansion for exchange in solids and surfaces
• Generalized gradient approximation for solids and their surfaces
• Ab initio studies of electronic structure of defects in PbTe
• Enhanced superconducting pairing interaction in indium-doped tin telluride
• Ab Initio Phonon Dispersions for PbTe
• Pressure-induced Topological Phase Transitions in Rock-salt Chalcogenides
• Fermi surface and electron dispersions of PbTe doped with resonant Tl impurity from KKR-CPA calculations
• Strain engineering of topological properties in lead-salt semiconductors

Cited by in corpus (7)

• Correlated local dipoles in PbTe
• Experimental evidence for topological surface states wrapping around bulk SnTe crystal
• Evidence of incoherent carriers associated with resonant impurity levels and their influence on superconductivity in the anomalous superconductor Pb${}_{1-x}$Tl${}_x$Te
• Direct spectroscopic evidence for mixed-valence Tl in the low carrier-density superconductor Pb${}_{1-x}$Tl${}_x$Te
• Experimental verification of band convergence in Sr and Na codoped PbTe
• A sharp increase in the density of states in PbTe approaching a saddle point in the band structure
• Finite size and volume effects in line node semimetals: a first-principles investigation