Physics – Condensed Matter – Superconductivity
Scientific paper
2011-10-18
Physics
Condensed Matter
Superconductivity
10 pages, 6 figures
Scientific paper
Interplay of superconductivity and magnetism in a composite prepared of the ferromagnetic half-metallic La_0.67Sr_0.33MnO (LSMO) nanoparticles and the conventional s-wave superconductor MgB_2 has been studied. A few principal effects have been found in bulk samples. With an onset of the MgB_2 superconductivity, a spectacular drop of the sample resistance has been detected and superconductivity has been observed at temperature up to 20K. Point-contact (PC) spectroscopy has been used to measure directly the superconducting energy coupling. For small voltage, an excess current and doubling of the PC's normal state conductance have been found. Conductance peaks corresponding to three energy gaps are clearly observed. Two of these gaps we identified as enhanced \Delta_{\pi} and \Delta_{\sigma} gaps originating from the MgB_2; the third gap \Delta_{tr} is more than three times larger than the largest MgB_2 gap. The experimental results provide unambiguous evidences for a new type of proximity effect which follows the phase coherency scenario of proximity induced superconductivity. Specifically, at low temperature, the p-wave spin-triplet condensate with pairing energy \Delta_{tr} is essentially sustained in LSMO but is incapable to display long-range supercurrent response because of a phase-disordering state. The proximity coupling to MgB_2 restores the long-range phase coherency of the triplet superconducting state, which, in turn, enhances superconducting state of the MgB_2.
Krivoruchko V. N.
Tarenkov Yu. V.
No associations
LandOfFree
Triple-gap superconductivity of MgB2 - (La,Sr)MnO3 composite. Which of the gaps is proximity induced? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Triple-gap superconductivity of MgB2 - (La,Sr)MnO3 composite. Which of the gaps is proximity induced?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Triple-gap superconductivity of MgB2 - (La,Sr)MnO3 composite. Which of the gaps is proximity induced? will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-290811