title: Resolving the wave vector in negative refractive index media.
abstract: We address the general issue of resolving the wave vector in complex electromagnetic media including negative refractive media. This requires us to make a physical choice of the sign of a square root imposed merely by conditions of causality. By considering the analytic behavior of the wave vector in the complex plane, it is shown that there are a total of eight physically distinct cases in the four quadrants of two Riemann sheets.
authors.affiliation: Department of Physics, Indian Institute of Technology, Kanpur-208 016, India. sar@iitk.ac.in
authors.forename: S Anantha
authors.initials: SA
authors.lastname: Ramakrishna
authors.forename: Olivier J F
authors.initials: OJ
authors.lastname: Martin