Invited Paper
Meta-Plasmonics: Natural vs Engineered Structures

Owing to the rapid development of the fields of nanotechnology and photonic metamaterials in recent years, new platforms and novel paradigms have become available for unconventional light-matter interaction in the wave optics as well as in the quantum optics scenarios. Natural structures such as noble metals and transparent dielectrics and artificially engineered platforms such as metamaterials have been introduced to manipulate waves in unprecedented ways in order to achieve certain useful functionalities. With these goals in mind, in my group we have been exploring various light-matter scenarios. Some of these include: (1) digital metamaterials [1] formed by building blocks of metamaterials “bits” and “bytes”, inspired by the notions of binary systems and digital electronics; (2) structural plasmonics, i.e., artificially engineered systems without using materials with negative permittivity, exhibiting plasmonic behaviors such as surface plasmon polaritons (SPP) and local surface plasmon resonance [2]; (3) extreme nanophotonics, in which metamaterials with extreme parameter values, such as epsilon-near-zero (ENZ) and/or mu-near-zero (MNZ), form an exciting paradigm for light-matter interaction at the extreme [e.g., 3,4]. Several exciting phenomena such as enhancement of emission of optical emitters and unusual entanglement and collective emission of emitters may occur in such structures; (4) material-based, wave-based, analog computing, where the wave-interaction with properly designed material structures can lead to performing mathematical functions on the waves at the nanoscale [5]; (5) nonreciprocal nanostructures involving extreme metamaterials for unusual flow of photons, with possibility of topologically protected photonic states with the magnetized ENZ structures [6,7]; and more. In this talk, I will give an overview of some of these topics, and will mention possible future directions.

[1] C. Della Giovampaola and N. Engheta, Nature Materials, 13, 1115 (2014)

[2] C. Della Giovampaola and N. Engheta, “Waveguide Metamaterials”, manuscript in preparation.

[3] M. Silveirinha and N. Engheta, Phys. Rev. Lett., 97, 157403 (2006)

[4] A. M. Mahmoud and N. Engheta, Nature Communications, 5, 5638 (2014)

[5] A. Silva, F. Monticone, G. Castaldi, V. Galdi, A. Alu and N. Engheta, Science, 343, 160 (2014)

[6] A. Davoyan and N. Engheta, Phys. Rev. Lett., 111, 257401 (2013)

[7] A. Davoyan and N. Engheta, Nature Communications, 5, 5250 (2014)

engheta@ee.upenn.edu