Direct Observation of a Superconducting Vortex Diode
Abstract
The interplay between magnetism and superconductivity can lead to unconventional proximity and Josephson effects. A related phenomenon that has recently attracted considerable attention is the superconducting diode effect, in which a non-reciprocal critical current emerges. Although superconducting diodes based on superconducting/ferromagnetic (S/F) bilayers were demonstrated more than a decade ago, the precise underlying mechanism remains unclear. While not formally linked to this effect, the Fulde-Ferrell-Larkin-Ovchinikov (FFLO) state is a plausible mechanism, due to the 2-fold rotational symmetry breaking caused by the finite center-of-mass-momentum of the Cooper pairs. Here, we directly observe, for the first time, a tunable superconducting vortex diode in Nb/EuS (S/F) bilayers. Based on our nanoscale SQUID-on-tip (SOT) microscope and supported by in-situ transport measurements, we propose a theoretical model that captures our key results. Thus, we determine the origin for the vortex diode effect, which builds a foundation for new device concepts.
Keywords
Cite
@article{arxiv.2301.07121,
title = {Direct Observation of a Superconducting Vortex Diode},
author = {Alon Gutfreund and Hisakazu Matsuki and Vadim Plastovets and Avia Noah and Laura Gorzawski and Nofar Fridman and Guang Yang and Alexander Buzdin and Oded Millo and Jason W. A. Robinson and Yonathan Anahory},
journal= {arXiv preprint arXiv:2301.07121},
year = {2023}
}