We have recently introduced a new periodic metallic structure1 based on two interlaced lattices of straight wires2 and Split Ring Resonators3. The size of the scattering elements and the lattice constant are significantly less than the incident wavelength (at frequencies of interest), so that the system can be considered as an effective medium characterized by frequency-dependent material constants. By simulations and experimental measurements, we demonstrate a frequency band where both material constants—the permittivity (e) and permeability (m)—are simultaneously negative. When both material constants are negative, Maxwell’s Equations allow for plane wave solutions, but with a twist: ExB is in the direction of -k rather than +k for plane waves, and thus a "left-hand" rule relates the three vectors. The result of this simple reversal is that many common electromagnetic phenomena, such as the Doppler shift, Cerenkov radiation, and even Snell’s Law, are also reversed4, leading to the potential of novel electromagnetically active materials and surface coatings based on LH media.
1. D. R. Smith, W. J. Padilla, D. C. Vier, S. C. Nemat-Nasser, S. Schultz, Phys. Rev. Lett., 84, 4184 (2000).
2. J. B. Pendry, A. J. Holden, W. J. Stewart, I. Youngs, Phys. Rev. Lett. 76, 4773 (1996).
3. J. B. Pendry, A. J. Holden, D. J. Robbins, W. J. Stewart, IEEE Trans. MTT, 47, 2075 (1999).
4. V. G. Veselago, Soviet Physics USPEKHI 10, 509 (1968).