Zero-Phase-Difference Josephson Current Based on Spontaneous Symmetry Breaking via Parametric Excitation of a Movable Superconducting Dot
Journal article, 2017

Recent advances have attracted attention to nonstandard Josephson junctions in which a supercurrent can flow despite zero phase difference between the constituent superconducting leads. Here, we propose a zero-phase-difference nanoelectromechanical junction which, in contrast to other considered systems, exhibits symmetry between leftward and rightward tunneling through the junction. We show that a supercurrent is, nevertheless, possible as a result of spontaneous symmetry breaking. In the suggested junction, the supercurrent is mediated by tunneling via a superconducting Cooper-pair box on a mechanical resonator. An alternating electric potential parametrically excites mechanical oscillations which are synchronized with charge oscillations of the box. This leads to coherent transfer of Cooper pairs through the junction. The direction of the supercurrent is a result of spontaneous symmetry breaking and thus it can be reversed without changing the parameters.


nanoelectromechanical systems

Cooper-pair box


Martin Eriksson

Chalmers, Physics, Condensed Matter Theory

Anton Vikström

Chalmers, Physics, Condensed Matter Theory

Physical Review Letters

0031-9007 (ISSN) 1079-7114 (eISSN)

Vol. 118 19 197701- 197701

Areas of Advance

Nanoscience and Nanotechnology (SO 2010-2017, EI 2018-)

Subject Categories

Condensed Matter Physics





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