My group is involved in many aspects of research on engineered electromagnetic materials, or metamaterials. Some specific accomplishments are the first successful numerical simulation of subwavelength focusing with negative refractive index materials, and the first measurement of the spatial distribution of fields inside a metamaterial that directly demonstrated the unusual wave behavior that can be created with artificial metamaterials.
Our more recent work has focused on the development of what we and other researchers call functional metamaterials. These are metamaterials that, instead of just exhibiting specific but static electromagnetic material properties, actually do something interesting that conventional materials cannot do. This can be as simple as exhibiting strongly nonlinear behavior, or engineering external tunability into metamaterials, which we have done with with MEMS switches, BST variable capacitors, and amplifiers.
Our current focus is on engineering truly functional behavior into electromagnetic metamaterials. Examples include a limiter metamaterial that is transparent to low power signals but becomes more and more opaque as the incident power increases, and a nonreciprocal metamaterial that is transparent to signals traveling in one direction and opaque in the other (like a true one-way mirror).Some of Our Recent Papers on Electromagnetic Metamaterials
Engineering a nonreciprocal metamaterial that behaves differently for waves traveling in opposite directions: Popa, B.-I. and S. A. Cummer, Nonreciprocal active metamaterials
, Phys. Rev. B., v. 85, 205101, 2012. [pdf reprint
Design and demonstration of an electromagnetic limiter metamaterial: Katko, A. R., A. M. Hawkes, J. P. Barrett, and S. A. Cummer, Metamaterial RF limiter using PIN diodes
, IEEE AWPL, v. 10, p. 1571, 2011. [pdf reprint
Design and demonstration of a phase conjugation or time reversal metamaterial: Katko, A. R., S. Gu, J. P. Barrett, B.-I. Popa, G. Shvets, and S. A. Cummer (2010), Phase conjugation and negative refraction using nonlinear active metamaterials
, Phys. Rev. Lett., v. 105, 123905. [pdf reprint