Related papers: Andreev reflection in Au/La_{2-x}Sr_{x}CuO_{4} poi…
We present new Au/La_{2-x}Sr_{x}CuO_{4} (LSCO) point-contact conductance measures as a function of voltage and temperature in samples with 0.08 <= x <= 0.2. Andreev reflection features disappear at about the bulk Tc, giving no evidence of…
We studied the voltage and temperature dependency of the dynamic conductance of normal metal-MgB2 junctions obtained either with the point-contact technique (with Au and Pt tips) or by making Ag-paint spots on the surface of high-quality…
Point-contact Andreev reflection spectroscopy at low temperatures and high magnetic fields has been performed on a noncentrosymmetric La$_3$Se$_4$ superconductor with a critical temperature $T_c$ = 8 K. Two superconducting energy gaps…
We propose that, if the pseudogap state in the cuprate superconductors can be described in terms of the phase-incoherent preformed pairs, there should exist Andreev reflection from these pairs even above the superconducting transition…
Conductance spectra measurements of highly transparent ramp-type junctions made of superconducting $La_{2-x}Sr_{x}CuO_4$ electrodes and non superconducting $La_{1.65}Sr_{0.35}CuO_4$ barrier are reported. At low temperatures below $T_c$,…
Directional point-contact Andreev-reflection spectroscopy measurements on the Ba$_{0.55}$K$_{0.45}$Fe$_2$As$_2$ single crystals are presented. The spectra show significant differences when measured in the $ab$ plane in comparison with those…
We perform a point-contact Andreev reflection spectroscopic study of the topological superconducting material, Cu0.25Bi2Se3, in the ballistic regime using a normal-metal gold tip. We observe distinct point-contact spectra on the…
We analyze the results of point-contact measurements in La_{2-x}Sr_{x}CuO_{4} (LSCO) previously reported as a clear evidence of the separation between gap and pseudogap in this copper oxide. Here we show that, in addition to this, the…
Experimental support is found for the multiband model of the superconductivity in the recently discovered system MgB2 with the transition temperature Tc = 39 K. By means of Andreev reflection evidence is obtained for two distinct…
A deep understanding of the character of superconductivity in the recently discovered Fe-based oxypnictides ReFeAsO1-xFx (Re = rare-earth) necessarily requires the determination of the number of the gaps and their symmetry in k space, which…
In this paper, we review some of our ARPES results on the superconducting and pseudo gaps in Bi2Sr2CaCu2O8+x. We find that optimally and overdoped samples exhibit a d-wave gap, which closes at the same temperature, Tc, for all k points. In…
We present the results of point-contact spectroscopy measurements in polycrystalline RuSr_2GdCu_2O_8 samples previously characterized from both the structural and the electrical point of view. AC susceptibility and resistivity measurements,…
We report point contact measurements in high quality single crystals of Cu0.2Bi2Se3. We observe three different kinds of spectra: (1) Andreev-reflection spectra, from which we infer a superconducting gap size of 0.6mV; (2) spectra with a…
The results of Point Contact Andreev Reflection Spectroscopy on polycrystalline RuSr$_2$GdCu$_2$O$_8$ pellets are presented. The wide variety of the measured spectra are all explained in terms of a modified BTK model considering a…
Sub-gap conductance at a large area junction with a rough interface of a ferromagnet and a high-T$_{C}$ superconductor is superimposed by multiple peaks which is not expected from an ideal point contact Andreev reflection process. We…
Point contact Andreev reflection studies have been conducted on FeSe single crystals by lowering the temperatures down to 0.5 K. The point contact Andreev reflection spectra were analyzed in the framework of the two-band model. As a result,…
Dynamic conductance spectra are taken from Au/CeCoIn$_5$ point contacts in the Sharvin limit along the (001) and (110) directions. Our conductance spectra, reproducibly obtained over wide ranges of temperature, constitute the cleanest data…
Point-contact Andreev-reflection measurements were performed in SmFeAsO_{0.8}F_{0.2} polycrystals with T_c \simeq 53 K. The experimental conductance curves reproducibly exhibit peaks around \pm 6 mV and shoulders at V \sim 16-20 mV,…
We have measured the temperature dependence of gap features revealed by Andreev reflection Delta_s and by tunneling Delta in the ab-plane of optimal and slightly overdoped microcrystals of (BiPb)2Sr2Ca2Cu3O10 (Bi2223) with critical…
Relationship between the superconducting gap and the pseudogap has been the subject of controversies. In order to clarify this issue, we have studied the superconducting gap and pseudogap of the high-Tc superconductor La2-xSrxCuO4 (x=0.10,…