2001/03/31 by К. Flachbart, K. Flachbart, K. Gloos +7 · 2 citations
Chemistry · Earth and Planetary Sciences · Physics and Astronomy · #Computer science #High-pressure geophysics and materials #Radioactive element chemistry and processing #Rare-earth and actinide compounds #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.64.085104
published as Phys. Rev. B 64, 085104 (2001) · 9 pages incl. 13 figures
arxiv created 2001/06/04 · openalex publication_date 2001/08/03 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We have investigated the intermediate valence narrow-gap semiconductor SmB6 at low temperatures using both conventional spear-anvil type point contacts as well as mechanically controllable break junctions. The zero-bias conductance varied between less than 0.01 \ensuremathμS and up to 1 mS. The position of the spectral anomalies, which are related to the different activation energies and band gaps of SmB6, did not depend on the the contact size. Two different regimes of charge transport could be distinguished: Contacts with large zero-bias conductance are in the diffusive Maxwell regime. They had spectra with only small nonlinearities. Contacts with small zero-bias conductance are in the tunneling regime. They had larger anomalies, but still indicating a finite 45% residual quasiparticle density of states at the Fermi level at low temperatures of T=0.1 K. The density of states derived from the tuneling spectra can be decomposed into two energy-dependent parts with Eg=21 meV and Ed=4.5 meV wide gaps, respectively.