The resistive transition of the Dy0.6Y0.4Rh3.85Ru0.15B4 sample into the superconducting state.
Representative set of the Andreev spectra (dI/dV(V)) for a typical contact with RN ≈ 3.7 Ω exhibiting a considerable enhancement of the gap structure in a magnetic field at T = 1.6 K. The BTK fitting of the spectra is shown by dash curves. The magnetic field is specified at each curve. The fitting revealed the tendency of the dimensionless barrier parameter Z to grow with the field, kOe: 0.1 (0); 0.13 (2.63); 0.16 (3.29); 0.26 (3.95); 0.34 (4.48); 0.42 (5.21); 0.34 (6.06), the smearing parameter Γ ≈ 0.1 meV being invariant. For clearness, the curves are arbitrarily displaced vertically.
Dynamic conductance versus the applied voltage for a Ta–Ag point contact (R = 3.56 Ω, T = 1.5 K) in different magnetic fields (0–899 mT).19
The dependence of the order parameter upon the magnetic field Δ(H) at T ≈ 1.6 K for the contact whose spectra are illustrated in Fig. 2. For comparison, two theoretical dependences (broken lines) are shown, which are possible in contacts based on conventional superconductors when the contact axis is along or perpendicular to the field.
A typical set of magnetic field PC spectra for one of the contacts with RN ≈ 5.5 Ω (solid lines). An acceptable coincidence of experimental and BTK-calculated spectra (broken lines) was obtained using invariant fitting parameters Z ≈ 0.1 and Γ ≈ 0.1 meV. For clearness, the curves are arbitrarily displaced vertically.
The BTK-calculated dependence of the order parameter on the magnetic field for the spectra shown in Fig. 5. For comparison, the figure illustrates two theoretical dependences (broken lines) expected for contacts based on conventional singlet superconductors.
Article metrics loading...
Full text loading...