Observation of double-gap-edge Andreev reflection at Si/Nb interfaces by point-contact spectroscopy

1994 ◽  
Vol 49 (15) ◽  
pp. 10484-10494 ◽  
Author(s):  
D. R. Heslinga ◽  
S. E. Shafranjuk ◽  
H. van Kempen ◽  
T. M. Klapwijk
Keyword(s):  
Andreev Reflection ◽  
Point Contact ◽  
Point Contact Spectroscopy

scholarly journals POINT-CONTACT SPECTROSCOPY OF MAGNESIUM DIBORIDE WITH DIFFERENT COUNTER-ELECTRODES

2003 ◽  
Vol 17 (27n28) ◽  
pp. 1405-1416
Author(s):  
A. I. D'YACHENKO ◽  
V. YU. TARENKOV ◽  
M. A. BELOGOLOVSKII ◽  
V. N. VARYUKHIN ◽  
A. V. ABAL'OSHEV ◽  
...  
Keyword(s):  
Andreev Reflection ◽  
Magnesium Diboride ◽  
Three Dimensional ◽  
Point Contact ◽  
Band Model ◽  
Counter Electrodes ◽  
Break Junctions ◽  
Point Contact Spectroscopy ◽  
Dc Current ◽  
Two Band Model

We report on tunneling and Andreev-reflection conductance spectra of 39 K superconducting magnesium diboride, obtained with Pb and Au counter-electrodes. Two distinct steps at close to 2.7 and 7.1 meV appear in a low-resistance metallic-type Au–MgB 2 junction characteristic, whereas a tunneling-like spectrum measured for the same junction, annealed by the application of DC current, exhibits only a rounded contribution of the larger gap. Junctions with a superconducting lead counter-electrode pressed into a bulk MgB 2 sample reveal two conductance peaks that are interpreted as the result of the formation of a highly-transmitting break junctions inside the magnesium diboride ceramic. Our results strongly support the two-band model with two different gap values on quasi-two-dimensional σ (7.1 meV) and three-dimensional π (2.7 meV) Fermi surface sheets of MgB 2.

Direct determination of the Andreev reflection probability by means of point contact spectroscopy

2000 ◽  
Vol 76 (9) ◽  
pp. 1152-1154 ◽  
Author(s):  
M. Jakob ◽  
H. Stahl ◽  
J. Knoch ◽  
J. Appenzeller ◽  
B. Lengeler ◽  
...  
Keyword(s):  
Andreev Reflection ◽  
Point Contact ◽  
Direct Determination ◽  
Point Contact Spectroscopy ◽  
Reflection Probability

scholarly journals Point Contact Spectroscopy on RuSr2GdCu2O8

2003 ◽  
Vol 17 (18n20) ◽  
pp. 3525-3529 ◽  
Author(s):  
F. Giubileo ◽  
F. Bobba ◽  
M. Gombos ◽  
S. Uthayakumar ◽  
A. Vecchione ◽  
...  
Keyword(s):  
Andreev Reflection ◽  
Magnetic Transition ◽  
Point Contact ◽  
Superconducting Transition ◽  
Temperature Behaviour ◽  
Point Contact Spectroscopy

We report the first tunneling experiments performed by means of point-contact technique on the ruthenate-cuprate RuSr 2 GdCu 2 O 8 (Ru1212) compound. Spectroscopy has been carried out on polycrystals characterized by superconducting transition at TC(ρ = 0) ≃ 26 K and magnetic transition at TM ≃ 133 K . A chemically etched copper tip has been used like normal counterelectrode. Very stable N-S contacts (N = Cu, S = Ru1212) have been obtained, clearly showing dI/dV spectra in the Andreev reflection regime. Temperature behaviour of the spectra has been measured in the range 4.2 K ≤ T ≤ 30 K . The dI/dV spectra seem to indicate important depairing effects in the Ru1212 and we discuss possible explanation.

Point-contact spectroscopy of quasi-1D conductors with CDW

1999 ◽  
Vol 09 (PR10) ◽  
pp. Pr10-179-Pr10-181
Author(s):  
A. A. Sinchenko ◽  
Yu. I. Latyshev ◽  
S. G. Zybtsev ◽  
I. G. Gorllova
Keyword(s):  
Point Contact ◽  
Point Contact Spectroscopy
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