132 research outputs found
Fabrication of submicron LaSrCuO intrinsic Josephson junction stacks
Intrinsic Josephson junction (IJJ) stacks of cuprate superconductors have
potential to be implemented as intrinsic phase qubits working at relatively
high temperatures. We report success in fabricating submicron
LaSrCuO (LSCO) IJJ stacks carved out of single crystals. We
also show a new fabrication method in which argon ion etching is performed
after focused ion beam etching. As a result, we obtained an LSCO IJJ stack in
which resistive multi-branches appeared. It may be possible to control the
number of stacked IJJs with an accuracy of a single IJJ by developing this
method.Comment: 5 pages, 6 figure
Holes in the valence band of superconducting boron-doped diamond film studied by soft X-ray absorption and emission spectroscopy
Carbon- and boron-2 states of superconducting and non-superconducting
boron-doped diamond samples are measured using soft X-ray emission and
absorption spectroscopy. For the superconducting sample, a large density of
hole states is observed in the valence band in addition to the states in the
impurity band. The hole states in the valence band is located at about 1.3 eV
below the valence band maximum regardless of the doping level, which cannot be
interpreted within a simple rigid band model. Present experimental results,
combined with the first principles calculations, suggest that superconductivity
is to be attributed to the holes in the valence band.Comment: 4 pages, 4 figure
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