Detection of Individual Vortices in Micron-Size Sr2RuO4 Rings by Phase-Locked Cantilever Magnetometry

TL;DR

This paper introduces a sensitive cantilever magnetometry technique that detects individual vortices in micron-sized Sr2RuO4 rings, achieving high resolution at low magnetic fields, and observes vortex entry with quantized magnetic moment jumps.

Contribution

The paper presents a novel feedback-based dynamic cantilever magnetometry method capable of detecting single vortices in mesoscopic superconducting rings at low fields.

Findings

Detected individual vortices in Sr2RuO4 rings

Achieved magnetic moment resolution of 7x10^-16 e.m.u.

Observed periodic vortex entry in mesoscopic rings

Abstract

We describe a feedback-based dynamic cantilever magnetometry technique capable of achieving high magnetic moment sensitivity with low applied fields. Using this technique, we have observed periodic entry of vortices into mesoscopic Sr2RuO4 rings. The quantized jump in the magnetic moment of the particle produced by individual vortices was measured with a resolution of 7x10^-16 e.m.u. at an applied field of 1 Oe.