Signatures of Complex Optical Response in Casimir Interactions of Type I and II Weyl Semimetals
arXiv:1911.03377 · doi:10.1038/s43246-020-0015-4
Abstract
The Casimir interaction is induced by electromagnetic fluctuations between objects and it is strongly dependent upon the electronic and optical properties of the materials making up the objects. Here we investigate this ubiquitous interaction between Weyl semimetals, a class of 3D systems with low energy linear dispersion and nontrivial topology due to symmetry conditions and stemming from separated energy cones. A comprehensive examination of all components of the bulk conductivity tensor as well as the surface conductivity due to the Fermi arc states in real and imaginary frequency domains is presented using the Kubo formalism for Weyl semimetals with different degree of tilting of their linear energy cones. The Casimir energy is calculated using a generalized Lifhsitz approach, for which electromagnetic boundary conditions for anisotropic materials were derived and used. We find that the Casimir interaction between Weyl semimetals is metallic-like and its magnitude and characteristic distance dependence can be modified by the degree of tilting and chemical potential. The nontrivial topology plays a secondary role in the Casimir interaction of these 3D materials and thermal fluctuations are expected to have similar effects as in metallic systems.
supplementary information added
References in corpus (10)
- Discovery of Weyl fermion semimetals and topological Fermi arc states
- Tunable Casimir repulsion with three dimensional topological insulators
- The Casimir force and the quantum theory of lossy optical cavities
- Demonstration of the Casimir force between ferromagnetic surfaces of a Ni-coated sphere and a Ni-coated plate
- Lifshitz-type formulas for graphene and single-wall carbon nanotubes: van der Waals and Casimir interations
- Casimir Force Phase Transitions in the Graphene Family
- Repulsive Casimir force between Weyl semimetals
- Absorption of circular polarized light in tilted Type-I and II Weyl semimetals
- Nonlocal Optical Response in Topological Phase Transitions in the Graphene Family
- Coexistence of Fermi arcs with two dimensional gapless Dirac states