Electromotive interference in a mechanically oscillating superconductor

François Konschelle (1) , Yaroslav M. Blanter (1)

1 Kavli institute of Nanoscience

We consider the superconducting phase in a moving superconductor and show that it depends on the displacement flux. Generalized constitutive relations between the phase of a superconducting interference device (SQUID) and the position of the oscillating part of its loop are then established. In particular, we show that the Josephson current and voltage depend on both the oscillator position and velocity. The two proposed relativistic corrections to the Josephson relations come from the macroscopic displacement of a quantum condensate according to the (non-)Galilean covariance of the Schr\"{o}dinger equation, and the kinematic displacement of the quasi-classical interfering path. In particular, we propose an alternative demonstration for the London rotating superconductor effect (also known as the London moment) using the covariance properties of the Schr\"{o}dinger equation. As an illustration, we show how these electromotive effects may induce self-sustained oscillations of a mechanical system.

Domaines: Supraconductivité [cond-mat.supr-con]; Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]

François Konschelle, Yaroslav M. Blanter. Electromotive interference in a mechanically oscillating superconductor. 2011. ⟨hal-00629315v1⟩