Issue
EPL
Volume 83, Number 6, September 2008
Article Number 67007
Number of page(s) 4
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
DOI http://dx.doi.org/10.1209/0295-5075/83/67007
Published online 12 September 2008
EPL, 83 (2008) 67007
DOI: 10.1209/0295-5075/83/67007

Negative refractive index of energy flow in Veselago materials

Nian-Hai Shen1, Hui-Tian Wang1 and Yongjun Tian2

1    Nanjing National Laboratory of Microstructures and Department of Physics, Nanjing University Nanjing 210093, China
2   Key Laboratory of Metastable Materials Science and Technology, Yanshan University - Qinhuangdao 066004, China

htwang@nju.edu.cn

received 20 May 2008; accepted in final form 6 August 2008; published September 2008
published online 12 September 2008

Abstract
In 1968, Veselago theoretically pioneered a new kind of electromagnetic materials with simultaneously negative permittivity and permeability, called Veselago materials here. Both theoretical simulations and experimental evidences have verified the irrefutable fact of negative refraction. A widely spread opinion is that the refractive index of a Veselago material must be negative in the literature. Here we argue this opinion, and present the concept of the refractive index of energy flow and the analogue Snell's law of energy flow. We reveal the underlying physics behind negative refraction in the Veselago material, indicating that the refractive index is positive while the refractive index of energy flow is indeed negative.

PACS
78.20.Ci - Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity).
42.25.Bs - Wave propagation, transmission and absorption.

© EPLA 2008