Demonstration of the Casimir force between ferromagnetic surfaces of a Ni-coated sphere and a Ni-coated plate

TL;DR

This study experimentally demonstrates the Casimir force between ferromagnetic surfaces, confirming Lifshitz theory predictions and highlighting the importance of magnetic properties over patch potential effects.

Contribution

First experimental demonstration of the Casimir force between ferromagnetic surfaces aligning with Lifshitz theory predictions.

Findings

Excellent agreement with Lifshitz theory for magnetic surfaces

Patch potentials have opposite effects in magnetic materials

Supports plasma model approach over Drude model for magnetic Casimir interactions

Abstract

We demonstrate the Casimir interaction between two ferromagnetic boundary surfaces using the dynamic atomic force microscope. The experimental data are found to be in excellent agreement with the predictions of the Lifshitz theory for magnetic boundary surfaces combined with the plasma model approach. It is shown that for magnetic materials the role of hypothetical patch potentials is opposite to that required for reconciliation of the data with the Drude model.