Origin of the Repulsive Casimir Force in Giant Polarization-Interconversion Materials

Achieving strong repulsive Casimir forces through engineered coatings can pave the way for micro- and nano-electromechanical applications where adhesive currently cause reliability issues. Here, we exploit Lifshitz theory to identify requirements in gyrotropic media two limiting cases (ultra-strong gyroelectric non-gyroelectric). We show that origin of force with gyrotropy such as Weyl semi-metals arises from giant interconversion polarization vacuum fluctuations.