18 research outputs found
Combined breakdown of a dielectric nanolayer to form a Josephson bridge
Electrical breakdown of a dielectric nanolayer between film electrodes under
the combined action of direct current and capacitor discharge current makes it
possible to form Josephson bridges with a reproducible resistance exceeding 1
{\Omega}. A new feature of the formation of a bridge during electrical
breakdown, which is preceded by a series of preliminary breakdowns (auto
breakdowns) of a dielectric nanolayer, has been discovered. The mechanism of
the process and the role of the thickness of the cathode film in the formation
of the bridge are discussed.Comment: 10 pages, 4 figure
Electrical breakdown of a dielectric for the formation of a superconducting nanocontact
Electrical breakdown of the dielectric nanolayer between film electrodes of
niobium and an alloy of 50% indium and 50% tin forms a bridge of this alloy
between the electrodes. The bridge resistance depends on the breakdown current.
The length of the bridge is equal to the thickness of the dielectric (30 nm),
and its diameter is 25 nm. The calculated coherence length of the alloy at 0 K
is close to the length of the bridge. The calculated critical current of a
bridge with a resistance of 1 {\Omega} at a temperature of 0 K is 2 mA. It is
concluded that such a bridge should have the properties of a Josephson contact
at a temperature lower than the critical temperature of the alloy (6.5 K).Comment: 11 pages, 7 figure