Enhanced repulsive Casimir forces between gold and thin magnetodielectric plates

Abstract: We calculate repulsive Casimir forces between metallic and magnetic plates and quantitatively probe the magnetic plate's properties as tuning knobs for the repulsion. Namely, the plate's thickness and its low-frequency permittivity and permeability. For a thin magnetic plate ($\leq 10\,\text{nm}$), we find that repulsion can exist as long as $\mu(0) \geq \epsilon(0)$. We also explore the effect of temperature on the repulsion and transition distance between attractive and repulsive interactions. We show how the parameters can be tuned to allow repulsion at sub-micron separation regimes, making it potentially accessible to known high-resolution measurement techniques using magnetic van der Waals materials.