Magnetic flux imaging in a 3D superconductor integrated circuit

TL;DR

This study visualizes magnetic flux patterns in a multilayer superconductor circuit, revealing complex flux behaviors during magnetization that inform better protection and resilience strategies for superconducting electronics.

Contribution

It introduces a novel magnetic flux imaging technique for multilayer superconductor circuits, providing detailed insights into flux propagation and screening effects.

Findings

Complex flux distributions are observed during magnetization.

Flux patterns are explained by Meissner screening and critical currents.

Results suggest ways to improve circuit protection against magnetic fields.

Abstract

We report on imaging magnetic flux distributions in a multilayered superconductor integrated circuit which emerge during magnetization and after field cooling of the circuit in the DC magnetic field. The obtained complicated field maps expose the flux propagation across the patterned superconducting ground planes sandwiching layers with Josephson junction-based logic cells, fine wire grid around the functional units, and multiple superconducting fill structures located in different inner layers. The observed intricate flux distributions are explained by specific patterns of Meissner screening currents and superconducting critical currents in different mutually interacting parts of the integrated circuit. Our results provide important insights into possible ways of improving the protection of superconductor integrated circuits from magnetic fields and their resilience against flux trapping.