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arXiv · 0708.2624

Josephson junctions with negative second harmonic in the current-phase relation: properties of novel varphi-junctions

E. Goldobin·D. Koelle·R. Kleiner·A. Buzdin
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Abstract

Several recent experiments revealed a change of the sign of the first harmonic in the current-phase relation of Josephson junctions (JJ) based on novel superconductors, e.g., d-wave based or JJ with ferromagnetic barrier. In this situation the role of the second harmonic becomes dominant and it determines the scenario of a 0-pi transition. We discuss different mechanisms of the second harmonic generation and its sign. If the second harmonic is negative the 0-pi transition becomes continuous and the realization of the so-called varphi junction is possible. We study the unusual properties of such a novel JJ and analyze the possible experimental techniques for their observation.

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E. Goldobin, D. Koelle, R. Kleiner, A. Buzdin. 2007-08-20. Josephson junctions with negative second harmonic in the current-phase relation: properties of novel varphi-junctions. https://doi.org/10.1103/physrevb.76.224523

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