Co-reporter:Iñigo Liberal
PNAS 2017 Volume 114 (Issue 5 ) pp:822-827
Publication Date(Web):2017-01-31
DOI:10.1073/pnas.1611924114
Vacuum fluctuations are one of the most distinctive aspects of quantum optics, being the trigger of multiple nonclassical
phenomena. Thus, platforms like resonant cavities and photonic crystals that enable the inhibition and manipulation of vacuum
fluctuations have been key to our ability to control light–matter interactions (e.g., the decay of quantum emitters). Here,
we theoretically demonstrate that vacuum fluctuations may be naturally inhibited within bodies immersed in epsilon-and-mu-near-zero
(EMNZ) media, while they can also be selectively excited via bound eigenmodes. Therefore, zero-index structures are proposed
as an alternative platform to manipulate the decay of quantum emitters, possibly leading to the exploration of qualitatively
different dynamics. For example, a direct modulation of the vacuum Rabi frequency is obtained by deforming the EMNZ region
without detuning a bound eigenmode. Ideas for the possible implementation of these concepts using synthetic implementations
based on structural dispersion are also proposed.
Co-reporter:Iñigo Liberal;Ahmed M. Mahmoud;Brian Edwards;Yue Li
Science 2017 Volume 355(Issue 6329) pp:
Publication Date(Web):
DOI:10.1126/science.aal2672
Doped photonics
Doping semiconductor materials with impurity atoms enables control of the optoelectronic properties that enhance functionality. Liberal et al. describe numerically and experimentally an analogous doping effect for a group of photonic materials. They introduced a dielectric into an otherwise nonmagnetic material, which produced a magnetic response. The generality of the method should allow the design of photonic materials with enhanced and controlled electromagnetic response.
Science, this issue p. 1058
Co-reporter:Artur R. Davoyan and Nader Engheta
ACS Photonics 2016 Volume 3(Issue 5) pp:
Publication Date(Web):April 15, 2016
DOI:10.1021/acsphotonics.5b00503
Here we discuss theoretically some of the notable features of modal characteristics in the graphene-coated deeply subwavelength fiber waveguide, providing a performance comparison between this guided-wave structure and some other typical THz waveguides. We highlight a cutoff-free propagation of a fundamental graphene-plasmon mode with an effective mode area, which can in principle be smaller than (λ/100)2. We also discuss the phonon-plasmon hybridization that is expected for waveguides with polar dielectric core (e.g., SiO2 and SiC). We believe that this guiding structure, being at the intersection of optics and electronics, may pave the way for a variety of nanoscience applications.
Co-reporter:Yue Li;Iñigo Liberal;Cristian Della Giovampaola
Science Advances 2016 Volume 2(Issue 6) pp:e1501790
Publication Date(Web):10 Jun 2016
DOI:10.1126/sciadv.1501790
A microwave test bed for metatronic “lumped” circuitry is introduced by exploiting structural dispersion in waveguides.
Co-reporter:Iñigo Liberal
Science Advances 2016 Volume 2(Issue 10) pp:
Publication Date(Web):
DOI:10.1126/sciadv.1600987
Quantum emitters embedded in arbitrarily shaped epsilon-near-zero cavities can selectively excite both nonradiating and radiating modes.
Co-reporter:Yakir Hadad, Artur R. Davoyan, Nader Engheta, and Ben Z. Steinberg
ACS Photonics 2014 Volume 1(Issue 10) pp:1068
Publication Date(Web):September 23, 2014
DOI:10.1021/ph500278w
Graphene—a naturally occurring two-dimensional material with unique optical and electronic properties—serves as a platform for novel terahertz applications and miniaturized systems with new capabilities. Recent discoveries of unusual quantum magneto-transport and high magneto-optical activity in strong magnetic fields make graphene a potential candidate for nonreciprocal photonics. Here we propose a paradigm of a flatland graphene-based metasurface in which an extraordinary and quantized magneto-optical activity at terahertz and infrared is attained at low, on-chip-compatible, magnetizations (∼0.2–0.3 T). The proposed system essentially breaks the tight linkage between the strength of the magnetic biasing and the resulting magneto-optical response. We design a system extremely sensitive to the quantized spectrum of graphene Landau levels and predict up to 90° of Faraday rotation with just a single sheet of graphene. We also demonstrate how to resolve the quantum resonances at the macroscopic level in the far-field. Our results not only are of a fundamental interest, but, as we discuss, pave a way to conceptually new capabilities in a range of applications, including sensing, terahertz nanophotonics, and even cryptography.Keywords: Faraday effect; graphene; nonreciprocity; optical nanodevices; quasistatic resonators
Co-reporter:Alexandre Silva;Francesco Monticone;Giuseppe Castaldi;Vincenzo Galdi;Andrea Alù
Science 2014 Volume 343(Issue 6167) pp:160-163
Publication Date(Web):10 Jan 2014
DOI:10.1126/science.1242818
Computational Metamaterials
Optical signal processing of light waves can represent certain mathematical functions and perform computational tasks on signals or images in an analog fashion. However, the complex systems of lenses and filters required are bulky. Metamaterials can perform similar optical processing operations but with materials that need only be a wavelength thick. Silva et al. (p. 160; see the Perspective by Sihvola) present a simulation study that shows how an architecture based on such metamaterials can be designed to perform a suite of mathematical functions to create ultrathin optical signal and data processors.
Co-reporter:Ashkan Vakil, Nader Engheta
Optics Communications 2012 Volume 285(Issue 16) pp:3428-3430
Publication Date(Web):15 July 2012
DOI:10.1016/j.optcom.2012.02.029
Inspired by its analog from classic optics, we introduce one-atom-thick reflectors for infrared (IR) surface plasmon polaritons (SPP) surface waves based on graphene. Using numerical simulations, we first present the simple case of one-atom-thick straight-line mirror and then show how a one-atom-thick parabolic reflector (mirror) can be envisioned for focusing guided SPP waves on the graphene.
Co-reporter:Ashkan Vakil
Science 2011 Vol 332(6035) pp:1291-1294
Publication Date(Web):10 Jun 2011
DOI:10.1126/science.1202691
Simulations show that control of the conductivity of a region within a graphene sheet could guide optical waves.
Co-reporter:Andrea Alù and Nader Engheta
The Journal of Physical Chemistry C 2010 Volume 114(Issue 16) pp:7462-7471
Publication Date(Web):April 5, 2010
DOI:10.1021/jp9113267
Here we compare different nanoscale waveguiding geometries involving plasmonic materials for subdiffractive propagation at optical frequencies. Deriving closed-form analytical formulas to analyze the different structures, we show how the presence of a plasmonic background may produce robust, highly confined guided wave propagation as compared with the dual setups involving plasmonic particles in a transparent background. Advantages and disadvantages of different scenarios for realizing right-handed and left-handed propagation in one-dimensional (1D) and two-dimensional (2D) waveguides are highlighted and discussed.
Co-reporter:Gennady Shvets, Nader Engheta
Solid State Communications 2008 Volume 146(5–6) pp:197
Publication Date(Web):May 2008
DOI:10.1016/j.ssc.2008.01.042
