Optical Properties of a θ-Vacuum

Abstract

Chern-Simons (CS) forms generalize the minimal coupling between gauge potentials and point charges, to sources represented by charged extended objects (branes). The simplest example of such a CS-brane coupling is a domain wall coupled to the electromagnetic CS three-form. This describes a topologically charged interface where the CS form AdA is supported, separating two three-dimensional spatial regions in 3+1 spacetime. Electrodynamics at either side of the brane is described by the same Maxwell's equations, but those two regions have different vacua, characterized by a different value of the θ-parameter multiplying the Pontryagin form F ^ F. The θ-term is the abelian version of the concept introduced by 't Hooft for the resolution of the U(1) problem in QCD. We point out that CS-generalized classical electrodynamics shows new phenomena when two neighboring regions with different θ-vacua are present. These topological effects result from surface effects induced by the boundary and we explore the consequences of such boundary effects for the propagation of the electromagnetic field in Maxwell theory. Several features, including optical and electrostatic/magnetostatic responses, which may be observable in condensed matter systems, like topological insulators, are discussed.

11 pages, no figures

References in corpus (9)

• Topological Field Theory of Time-Reversal Invariant Insulators
• Tunable Casimir repulsion with three dimensional topological insulators
• Effect of finite temperature and uniaxial anisotropy on the Casimir effect with three-dimensional topological insulators
• Couplings between Chern-Simons gravities and 2p-branes
• Theta term in a bounded region
• Reflections on Cosmology: an Outsider's Point of View
• Geometry and stability of spinning branes in AdS gravity
• Extended Charged Events and Chern-Simons Couplings
• Naked Singularities, Topological Defects and Brane Couplings

Cited by in corpus (11)

• Green's function approach to Chern-Simons extended electrodynamics: an effective theory describing topological insulators
• Electro and magneto statics of topological insulators as modeled by planar, spherical and cylindrical $\theta$ boundaries: Green function approach
• Electromagnetic description of three-dimensional time-reversal invariant ponderable topological insulators
• The magnetoelectric coupling in Electrodynamics
• Van der Waals torque and force between anisotropic topological insulator slabs
• Magnetoelectric effect of a conducting sphere near a planar topological insulator
• Optical Properties Chern-Simons (3+1)D $\theta$-systems
• Gravitational waves propagation in nondynamical Chern-Simons gravity
• Optical intersubband properties of a core-shell semiconductor-topological insulator quantum dot described by $\theta$-Electrodynamics
• Transgression field theory at the interface of topological insulators
• The magnetoelectric effect due to a semispherical capacitor surrounded by a spherical topologically insulating shell