Adam, Sébastien
[UCL]
Piraux, Luc
[UCL]
Michotte, Sébastien
[UCL]
Lucot, D.
Mailly, D.
Applying current in type-II superconducting sub-micron size structures often leads to a discontinuity of the current-voltage characteristic as the instability current is reached. Also voltage-bias mode allows to avoid such an abrupt switch to the normal state, and gives a relevant outlook of the involved resistive phenomenons. Current and voltage-bias measurements on NbN microbridges with a constriction are reported here as a function of temperature and transverse magnetic field. Starting from a 75 nm -thick sputtered film, 160 nm -wide microstrips were patterned with an half-wide section constriction in their middle. From the current-bias curves it appears that the discontinuities are due to a flux flow instability that rapidly evolves in a hot-spot. Moreover applying the voltage reveals several dissipative states that leads to successive S-shaped current oscillations in a small current range. Formation of vortex channels can be considered to explain these features.
Bibliographic reference |
Adam, Sébastien ; Piraux, Luc ; Michotte, Sébastien ; Lucot, D. ; Mailly, D.. Non-equilibrium resistive states of superconducting NbN microstrips in a transverse magnetic field.25th International Conference on Low Temperature Physics (Amsterdam, Netherlands, 6-13 August 2008). |
Permanent URL |
http://hdl.handle.net/2078.1/67599 |