Article

Classical Analogue of Electromagnetically Induced Transparency with a Metal-Superconductor Hybrid Metamaterial

Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, Maryland 20742-4111, USA.
Physical Review Letters (Impact Factor: 7.51). 07/2011; 107(4):043901. DOI: 10.1103/PhysRevLett.107.043901
Source: PubMed

ABSTRACT

Metamaterials are engineered materials composed of small electrical circuits producing novel interactions with electromagnetic waves. Recently, a new class of metamaterials has been created to mimic the behavior of media displaying electromagnetically induced transparency (EIT). Here we introduce a planar EIT metamaterial that creates a very large loss contrast between the dark and radiative resonators by employing a superconducting Nb film in the dark element and a normal-metal Au film in the radiative element. Below the critical temperature of Nb, the resistance contrast opens up a transparency window along with a large enhancement in group delay, enabling a significant slowdown of waves. We further demonstrate precise control of the EIT response through changes in the superfluid density. Such tunable metamaterials may be useful for telecommunication because of their large delay-bandwidth products.

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Available from: Alexander P. Zhuravel, Feb 01, 2016
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    • "Among those efforts, electromagnetically induced transparency (EIT) in three-level atomic systems is one of the most compelling ideas [1] [2] [3]. A classical analog of EIT atomic systems is realized in structured metamaterials that have a radiative mode coupled to a trapped mode [4] [5] [6]. The interaction between two modes induces a narrow transparency window in which light propagates with low absorption, also creating strong dispersion and a substantial slowing of light [1–4,6]. "

    Full-text · Article · Dec 2015 · Physical Review X
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    • "It is known that EIT-like phenomena can in principle be observed in classical systems due to the fact that some aspect of the atom-field interaction can be described by the classical theory of optical dispersion [11], and no quantum mechanical states are necessary to observe EIT in metamaterials. Recently, it has been shown that such system supports a dark state leading to phenomena similar to EIT, can be represented by a wide variety of classical analogues: plasmonic structure [10], metal-superconductor hybrid metamaterial [17], coupled microresonators [18] or cut wire-pairs [19]. The simplest and the most intuitive model of such a system consists of two harmonic oscillators coupled by a spring, shown on the Fig. 1 (b) [11]. "
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    ABSTRACT: Nowadays, there is considerable interest in metamaterials which realize the electromagnetically induced transparency in a classical system. We consider the frequency shifts of particle moving in metamaterials exhibiting electromagnetically induced transparency effect. The dramatic change of the material dispersion due to the EIT influences the conditions for signal propagation in the medium and has a significant impact on the Doppler effect, possibly leading to the optical control over this phenomenon. The dependence of the Doppler shift to the source frequency and velocity and radiation spectra on external parameters is examined. It was found that for source frequencies fitting transparency window for particular range of source velocities cutoffs appear, i.e. the radiation is not emitted. Our theoretical findings are proved analytically and confirmed by numerical simulations based on finite-difference time-domain method.
    Full-text · Article · Nov 2015
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    • "In order to realize practical applications, including the storage of electromagnetic waves, the tunability of the EIT-like effects is quite important. Many researchers have reported various methods to tune EIT-like metamaterials in a passive manner by changing the incident angles [39] [40] and in active manners by conductivity modulation utilizing diodes [41], superconductors [42] [43], and photo-carrier excitation in a semiconductor [44] [45], or by tuning an external magnetic field [36]. Recently, we proposed an EIT-like metamaterial whose properties can be controlled by applying bias voltages to diodes to change their capacitances, and we experimentally demonstrated the storage of electromagnetic waves in the microwave region [46]. "
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    ABSTRACT: We propose a metamaterial to realize true electromagnetically induced transparency (EIT), where the incidence of an auxiliary electromagnetic wave called the control wave induces transparency for a probe wave. The analogy to the original EIT effect in an atomic medium is shown through analytical and numerical calculations derived from a circuit model for the metamaterial. We performed experiments to demonstrate the EIT effect of the metamaterial in the microwave region. The width and position of the transparent region can be controlled by the power and frequency of the control wave. We also observed asymmetric transmission spectra unique to the Fano resonance.
    Full-text · Article · Aug 2015 · Physical Review Applied
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