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arXiv · 1111.5091

Quantum crossover in moderately damped epitaxial NbN/MgO/NbN junctions with low critical current density

Luigi Longobardi·Davide Massarotti·Giacomo Rotoli·Daniela Stornaiuolo·Gianpaolo Papari·Akira Kawakami·Giovanni Piero Pepe·Antonio Barone·Francesco Tafuri
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Abstract

High quality epitaxial NbN/MgO/NbN Josephson junctions have been realized with MgO barriers up to a thickness of d=1 nm. The junction properties coherently scale with the size of barrier, and low critical current densities down to 3 A/cm$^2$ have been achieved for larger barriers. In this limit, junctions exhibit macroscopic quantum phenomena for temperatures lower than 90 mK. Measurements and junction parameters support the notion of a possible use of these devices for multiphoton quantum experiments, taking advantage of the fast non equilibrium electron-phonon relaxation times of NbN.

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Luigi Longobardi, Davide Massarotti, Giacomo Rotoli, Daniela Stornaiuolo, Gianpaolo Papari, Akira Kawakami, Giovanni Piero Pepe, Antonio Barone, Francesco Tafuri. 2011-11-22. Quantum crossover in moderately damped epitaxial NbN/MgO/NbN junctions with low critical current density. https://doi.org/10.1063/1.3624471

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