Experimental evidence of a φ Josephson junction

Sickinger, H., Lipman, A., Weides, M. , Mints, R.G., Kohlstedt, H., Koelle, D., Kleiner, R. and Goldobin, E. (2012) Experimental evidence of a φ Josephson junction. Physical Review Letters, 109(10), 107002. (doi: 10.1103/PhysRevLett.109.107002) (PMID:23005318)

Abstract

We demonstrate experimentally the existence of Josephson junctions having a doubly degenerate ground state with an average Josephson phase ψ = ± φ . The value of φ can be chosen by design in the interval 0 < φ < π . The junctions used in our experiments are fabricated as 0- π Josephson junctions of moderate normalized length with asymmetric 0 and π regions. We show that (a) these φ Josephson junctions have two critical currents, corresponding to the escape of the phase ψ from − φ and + φ states, (b) the phase ψ can be set to a particular state by tuning an external magnetic field, or (c) by using a proper bias current sweep sequence. The experimental observations are in agreement with previous theoretical predictions.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Weides, Professor Martin
• Authors: Sickinger, H., Lipman, A., Weides, M., Mints, R.G., Kohlstedt, H., Koelle, D., Kleiner, R., and Goldobin, E.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: Physical Review Letters
• Publisher: American Physical Society
• ISSN: 0031-9007
• ISSN (Online): 1079-7114