2000/01/31 by András Halbritter, A. Halbritter, O. Yu. Kolesnychenko +5 · 1 citation
Engineering · Physics and Astronomy · #Metallic Glasses and Amorphous Alloys #Quantum and electron transport phenomena #Theoretical and Computational Physics #cond-mat.dis-nn #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.61.5846
published as Phys. Rev. B 61, 5846 (2000) · 4 pages, 5 figures
arxiv created 2000/02/01 · openalex publication_date 2000/03/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Bulk resistivity and point contact spectra of NixNb_1\ensuremath-x metallic glasses have been investigated as functions of temperature (0.3--300 K) and magnetic field (0--12 T). Metallic glasses in this family undergo a superconducting phase transition determined by the Nb concentration. When superconductivity was suppressed by a strong magnetic field, both the bulk sample R(T) and the point contact differential resistance curves of NixNb_1\ensuremath-x showed logarithmic behavior at low energies, which is explained by a strong electron-``two level system'' coupling. We studied the temperature, magnetic field, and contact resistance dependence of Ni44Nb56 point-contact spectra in the superconducting state and found telegraphlike fluctuations superimposed on superconducting characteristics. These R(V) characteristics are extremely sensitive detectors for slow relaxing ``two level system'' motion.