Casimir repulsion between Topological Insulators in the diluted regime

TL;DR

This paper investigates Casimir interactions between topological insulators in the diluted regime, revealing conditions for stable equilibrium, attraction, or repulsion, and how these depend on temperature and optical response.

Contribution

It applies the Pairwise Summation Approximation to topological insulators, providing new insights into Casimir forces and equilibrium conditions in this context.

Findings

Stable equilibrium distance can exist depending on optical response.

Casimir repulsion or attraction depends on temperature and material properties.

Results are valid only in the diluted approximation, independent of geometry.

Abstract

The Pairwise Summation Approximation (PSA) of Casimir energy is applied to a system of two dielectrics with magnetoelectric coupling. In particular, the case of Topological Insulators (TI) is studied in detail. Depending on the the optical response of the TI, we obtain a stable equilibrium distance, atraction for all distances, or repulsion for all distances at zero temperature. This equilibrium distance disappears in the high temperature limit. These results are independent on the geometry of the TI, but are only valid in the diluted approximation.