Microtraps for neutral atoms using superconducting structures in the critical state

TL;DR

This paper experimentally observes the hysteretic supercurrent distribution in type-II superconducting atom-chips, confirming the Bean model, and explores how this memory effect enables permanent current storage for advanced atom trapping.

Contribution

It provides the first experimental validation of the Bean model's predictions for supercurrent distribution in superconducting atom-chips, highlighting the potential for engineered trapping potentials.

Findings

Memory effect observed in supercurrent distribution

Results agree with Bean model predictions

Enables permanent current storage in superconducting structures

Abstract

Recently demonstrated superconducting atom-chips provide a platform for trapping atoms and coupling them to solid-state quantum systems. Controlling these devices requires a full understanding of the supercurrent distribution in the trapping structures. For type-II superconductors, this distribution is hysteretic in the critical state due to the partial penetration of the magnetic field in the thin superconducting film through pinned vortices. We report here an experimental observation of this memory effect. Our results are in good agreement with the redictions of the Bean model of the critical state without adjustable parameters. The memory effect allows to write and store permanent currents in micron-sized superconducting structures and paves the way towards new types of engineered trapping potentials.