Showing papers on "Electromagnetically induced transparency published in 2014"

All-dielectric metasurface analogue of electromagnetically induced transparency

Abstract: Metasurface analogues of electromagnetically induced transparency (EIT) have been a focus of the nanophotonics field in recent years, due to their ability to produce high-quality factor (Q-factor) resonances. Such resonances are expected to be useful for applications such as low-loss slow-light devices and highly sensitive optical sensors. However, ohmic losses limit the achievable Q-factors in conventional plasmonic EIT metasurfaces to values <~10, significantly hampering device performance. Here we experimentally demonstrate a classical analogue of EIT using all-dielectric silicon-based metasurfaces. Due to extremely low absorption loss and coherent interaction of neighbouring meta-atoms, a Q-factor of 483 is observed, leading to a refractive index sensor with a figure-of-merit of 103. Furthermore, we show that the dielectric metasurfaces can be engineered to confine the optical field in either the silicon resonator or the environment, allowing one to tailor light-matter interaction at the nanoscale.

What is and what is not electromagnetically induced transparency in whispering-gallery microcavities

Abstract: There has been an increasing interest in all-optical analogues of electromagnetically induced transparency and Autler–Townes splitting. Despite the differences in their underlying physics, both electromagnetically induced transparency and Autler–Townes splitting are quantified by a transparency window in the absorption or transmission spectrum, which often leads to a confusion about its origin. While the transparency window in electromagnetically induced transparency is a result of Fano interference among different transition pathways, in Autler–Townes splitting it is the result of strong field-driven interactions leading to the splitting of energy levels. Being able to tell objectively whether an observed transparency window is because of electromagnetically induced transparency or Autler–Townes splitting is crucial for applications and for clarifying the physics involved. Here we demonstrate the pathways leading to electromagnetically induced transparency, Fano resonances and Autler–Townes splitting in coupled whispering-gallery-mode resonators. Moreover, we report the application of the Akaike Information Criterion discerning between all-optical analogues of electromagnetically induced transparency and Autler–Townes splitting and clarifying the transition between them. Optical analogues of electromagnetically induced transparency and Autler–Townes splitting originate from different mechanisms but both are quantified by a transparency window. Here, Peng et al.use the Akaike information criterion to discriminate between the two regimes in coupled whispering gallery mode microresonators.

Broadband Rydberg Atom-Based Electric-Field Probe for SI-Traceable, Self-Calibrated Measurements

Abstract: We discuss a fundamentally new approach for the measurement of electric fields that will lead to the develop- mentofabroadband,directSI-traceable,compact,self-calibrating -field probe (sensor). This approach is based on the interaction of radio frequency (RF) fields with alkali atoms excited to Rydberg states. The RF field causes an energy splitting of the Rydberg states via the Autler-Townes effect and we detect the splitting via electromagnetically induced transparency. In effect, alkali atoms placed in a vapor cell act like an RF-to-optical transducer, converting an RF -field strength measurement to an optical frequency measurement. We demonstrate the broadband nature of this approach by showing that one small vapor cell can be used to measure -field strengths over a wide range of frequencies: 1 GHz to 500 GHz. The technique is validated by comparing experimental data to both numerical simulations and far-field calculations for various frequencies. We also discuss various applications, including: a direct traceable measurement, the ability to measure both weak and strong field strengths, compact form factors of the probe, and sub-wavelength imaging and field mapping. Index Terms—Atom based metrology, Autler-Townes splitting, broadband sensor and probe, electrical field measurements and sensor, electromagnetically induced transparency (EIT), Rydberg atoms, sub-wavelength imaging.

Single-photon switch based on Rydberg blockade.

Abstract: All-optical switching is a technique in which a gate light pulse changes the transmission of a target light pulse without the detour via electronic signal processing. We take this to the quantum regime, where the incoming gate light pulse contains only one photon on average. The gate pulse is stored as a Rydberg excitation in an ultracold atomic gas using electromagnetically induced transparency. Rydberg blockade suppresses the transmission of the subsequent target pulse. Finally, the stored gate photon can be retrieved. A retrieved photon heralds successful storage. The corresponding postselected subensemble shows an extinction of 0.05. The single-photon switch offers many interesting perspectives ranging from quantum communication to quantum information processing.

Optomechanical analog of two-color electromagnetically induced transparency: Photon transmission through an optomechanical device with a two-level system

Abstract: Some optomechanical systems can be transparent to a probe field when a strong driving field is applied. These systems can provide an optomechanical analog of electromagnetically induced transparency (EIT). We study the transmission of a probe field through a hybrid optomechanical system consisting of a cavity and a mechanical resonator with a two-level system (qubit). The qubit might be an intrinsic defect inside the mechanical resonator, a superconducting artificial atom, or another two-level system. The mechanical resonator is coupled to the cavity field via radiation pressure and to the qubit via the Jaynes-Cummings interaction. We find that the dressed two-level system and mechanical phonon can form two sets of three-level systems. Thus, there are two transparency windows in the discussed system. We interpret this effect as an optomechanical analog of two-color EIT (or double EIT). We demonstrate how to switch between one and two EIT windows by changing the transition frequency of the qubit. We show that the absorption and dispersion of the system are mainly affected by the qubit-phonon coupling strength and the transition frequency of the qubit.

Sub-wavelength imaging and field mapping via electromagnetically induced transparency and Autler-Townes splitting in Rydberg atoms

Abstract: We present a technique for measuring radio-frequency (RF) electric field strengths with sub-wavelength resolution. We use Rydberg states of rubidium atoms to probe the RF field. The RF field causes an energy splitting of the Rydberg states via the Autler-Townes effect, and we detect the splitting via electromagnetically induced transparency (EIT). We use this technique to measure the electric field distribution inside a glass cylinder with applied RF fields at 17.04 GHz and 104.77 GHz. We achieve a spatial resolution of ≈100 μm, limited by the widths of the laser beams utilized for the EIT spectroscopy. We numerically simulate the fields in the glass cylinder and find good agreement with the measured fields. Our results suggest that this technique could be applied to image fields on a small spatial scale over a large range of frequencies, up into the sub-terahertz regime.

Millimeter Wave Detection via Autler-Townes Splitting in Rubidium Rydberg Atoms

Abstract: In this paper, we demonstrate the detection of millimeter waves via Autler-Townes splitting in 85Rb Rydberg atoms This method may provide an independent, atom-based, SI-traceable method for measuring mm-wave electric fields, which addresses a gap in current calibration techniques in the mm-wave regime The electric-field amplitude within a rubidium vapor cell in the WR-10 wave guide band is measured for frequencies of 9371 GHz and 10477 GHz Relevant aspects of Autler-Townes splitting originating from a four-level electromagnetically induced transparency scheme are discussed We measured the E-field generated by an open-ended waveguide using this technique Experimental results are compared to a full-wave finite element simulation

Electromagnetically-induced-transparency-like ground-state cooling in a double-cavity optomechanical system

Abstract: We propose to cool a mechanical resonator close to its ground state via an electromagnetically-induced-transparency (EIT)-like cooling mechanism in a double-cavity optomechanical system, where an additional cavity couples to the original one in the standard optomechanical system. By choosing optimal parameters such that the cooling process of the mechanical resonator corresponds to the maximum value of the optical fluctuation spectrum and the heating process to the minimum one, the mechanical resonator can be cooled with the final mean phonon number less than that at the absence of the additional cavity. And we show the mechanical resonator may be cooled close to its ground state via such an EIT-like cooling mechanism even when the original resolved sideband condition is not fulfilled.

Cavity-enhanced room-temperature magnetometry using absorption by nitrogen-vacancy centers in diamond.

Abstract: Optical sensing of magnetic fields [1], electric fields [2,3], rotations [4–6], and temperature [7–10] can be achieved using negatively charged nitrogen-vacancy (NV) centers in diamond. Single NV centers and ensembles of NV centers can be detected with high spatial resolution and can be used as sensors with nm, μm, or mm resolution [11–14]. Most of these sensors are based on fluorescence detection of the NV center’s spin state and suffer from low photon detection efficiency and background fluorescence. Even with improved photon collection [15–17], current state-of-the-art magnetic field sensors [17] can only reach sensitivities which are several orders of magnitude worse than the quantum projection noise (PN) limited sensitivity [14,18] associated with the finite number of sensing spins. Sensors based on detection of infrared (IR) absorption [19] achieve high photon detection efficiency and can reach a sensitivity closer to the PN limit compared to sensors based on fluorescence detection when a cavity is used to enhance the detection contrast [20]. Previously, absorption of IR light has been used for magnetometry at cryogenic temperatures (∼70 K) [19] where the absorption is much stronger than at room temperature. In this work, a diamond plate is placed in an external cavity which enhances the absorption from the NV centers and the spin-state detection contrast. The device is used as a magnetic field sensor operated at room temperature, but could be used for other applications requiring high optical depth such as electromagnetically induced transparency [3]. Here the use of a cavity could enable low-power, high-fidelity nonlinear optical processes such as quantum optical storage [21]. The level structure of the NV center is shown in Fig.1(a). Electron spin-triplet and spin-singlet states are labeled 3 A2, 3 E and 1 E, 1 A1, respectively. The NV center can be excited optically from the ground state 3 A2 to the state 3 E. From the 3 E state, the NV center can decay to the 3 A2 state through a spin-conserving transition which leads to fluorescence in the 637–800 nm wavelength range. It can also decay to the upper singlet state 1 A1 through a spin-nonconserving transition, which occurs with higher probability for the ms ¼� 1 states compared to the ms ¼ 0 state [22,23]. From the 1 A1 state, the NV center decays through a 1042 nm transition to the metastable 1 E singlet state, which has a lifetime of ∼200 ns at room temperature [24]. The NV center then decays from the 1 E state back to

Tunable phonon-induced transparency in bilayer graphene nanoribbons.

Abstract: In the phenomenon of plasmon-induced transparency, which is a classical analogue of electromagnetically induced transparency (EIT) in atomic gases, the coherent interference between two plasmon modes results in an optical transparency window in a broad absorption spectrum. With the requirement of contrasting lifetimes, typically one of the plasmon modes involved is a dark mode that has limited coupling to the electromagnetic radiation and possesses relatively longer lifetime. Plasmon-induced transparency not only leads to light transmission at otherwise opaque frequency regions but also results in the slowing of light group velocity and enhanced optical nonlinearity. In this article, we report an analogous behavior, denoted as phonon-induced transparency (PIT), in AB-stacked bilayer graphene nanoribbons. Here, light absorption due to the plasmon excitation is suppressed in a narrow window due to the coupling with the infrared active Γ-point optical phonon, whose function here is similar to that of the dar...

Broadband Rydberg Atom-Based Electric-Field Probe: From Self-Calibrated Measurements to Sub-Wavelength Imaging

Abstract: We discuss a fundamentally new approach for the measurement of electric (E) fields that will lead to the development of a broadband, direct SI-traceable, compact, self-calibrating E-field probe (sensor). This approach is based on the interaction of radio frequency (RF) fields with alkali atoms excited to Rydberg states. The RF field causes an energy splitting of the Rydberg states via the Autler-Townes effect and we detect the splitting via electromagnetically induced transparency (EIT). In effect, alkali atoms placed in a vapor cell act like an RF-to-optical transducer, converting an RF E-field strength measurement to an optical frequency measurement. We demonstrate the broadband nature of this approach by showing that one small vapor cell can be used to measure E-field strengths over a wide range of frequencies: 1 GHz to 500 GHz. The technique is validated by comparing experimental data to both numerical simulations and far-field calculations for various frequencies. We also discuss various applications, including: a direct traceable measurement, the ability to measure both weak and strong field strengths, compact form factors of the probe, and sub-wavelength imaging and field mapping.

Sub-Wavelength Imaging and Field Mapping via EIT and Autler-Townes Splitting In Rydberg Atoms ∗

Abstract: We present a technique for measuring radio-frequency (RF) electric field strengths with sub-wavelength resolution. We use Rydberg states of rubidium atoms to probe the RF field. TheRF field causes an energy splitting of the Rydberg states via the Autler-Townes effect, and wedetect the splitting via electromagnetically induced transparency (EIT). We use this technique tomeasure the electric field distribution inside a glass cylinder with applied RF fields at 17.04 GHzand 104.77 GHz. We achieve a spatial resolution of ≈100 µm, limited by the widths of the laserbeams utilized for the EIT spectroscopy. We numerically simulate the fields in the glass cylinderand find good agreement with the measured fields. Our results suggest that this technique couldbe applied to image fields on a small spatial scale over a large range of frequencies, up into thesub-THz regime. ∗ This work was partially supported by DARPA’s QuASAR program. Publication of the U.S. government,not subject to U.S. copyright. †

Coherent control of the waveforms of recoilless γ-ray photons

Abstract: The resonant interaction between γ-ray photons and an ensemble of nuclei with a periodically modulated resonant transition frequency can be used to control the waveforms of the photons coherently; for example, individual γ-ray photons can be converted into a coherent, ultrashort pulse train or into a double pulse. The coherent manipulation of photons in the high-energy soft γ-ray to hard X-ray regime is desirable for a range of fundamental and practical applications, yet the tools available to achieve such manipulations remain limited. Farit Vagizov et al. have devised and implemented a scheme for coherently controlling the waveforms of single γ-photons. This work raises the prospect of using single γ-photons, rather than optical photons, in quantum communication and information processing. The concepts and ideas of coherent, nonlinear and quantum optics have been extended to photon energies in the range of 10–100 kiloelectronvolts, corresponding to soft γ-ray radiation (the term used when the radiation is produced in nuclear transitions) or, equivalently, hard X-ray radiation (the term used when the radiation is produced by electron motion). The recent experimental achievements in this energy range include the demonstration of parametric down-conversion in the Langevin regime1, electromagnetically induced transparency in a cavity2, the collective Lamb shift3, vacuum-assisted generation of atomic coherences4 and single-photon revival in nuclear absorbing multilayer structures5. Also, realization of single-photon coherent storage6 and stimulated Raman adiabatic passage7 were recently proposed in this regime. More related work is discussed in a recent review8. However, the number of tools for the coherent manipulation of interactions between γ-ray photons and nuclear ensembles remains limited. Here we suggest and implement an efficient method to control the waveforms of γ-ray photons coherently. In particular, we demonstrate the conversion of individual recoilless γ-ray photons into a coherent, ultrashort pulse train and into a double pulse. Our method is based on the resonant interaction of γ-ray photons with an ensemble of nuclei with a resonant transition frequency that is periodically modulated in time. The frequency modulation, which is achieved by a uniform vibration of the resonant absorber, owing to the Doppler effect, renders resonant absorption and dispersion both time dependent, allowing us to shape the waveforms of the incident γ-ray photons. We expect that this technique will lead to advances in the emerging fields of coherent and quantum γ-ray photon optics, providing a basis for the realization of γ-ray-photon/nuclear-ensemble interfaces and quantum interference effects at nuclear γ-ray transitions.

Two-photon dynamics in coherent Rydberg atomic ensemble.

Abstract: We study the interaction of two photons in a Rydberg atomic ensemble under the condition of electromagnetically induced transparency, combining a semiclassical approach for pulse propagation and a complete quantum treatment for quantum state evolution. We find that the blockade regime is not suitable for implementing photon-photon cross-phase modulation due to pulse absorption and dispersion. However, approximately ideal cross-phase modulation can be realized based on relatively weak interactions, with counterpropagating and transversely separated pulses.

Subwavelength microwave electric-field imaging using Rydberg atoms inside atomic vapor cells

Abstract: We have recently shown [Nat. Phys.8, 819 (2012)] that Alkali atoms contained in a vapor cell can serve as a highly accurate standard for microwave (MW) electric field strength as well as polarization. Here we show for the first time that Rydberg atom electromagnetically induced transparency can be used to image MW electric fields with unprecedented precision. The spatial resolution of the method is far into the subwavelength regime ∼λ/650 or 66 μm at 6.9 GHz. The electric field resolutions are similar to those we have already demonstrated ∼50 μV cm−1. Our experimental results agree with finite element calculations of test electric-field patterns.

Uniform theoretical description of plasmon-induced transparency in plasmonic stub waveguide

Abstract: We investigate a classic analog of electromagnetically induced transparency (EIT) in a metal-dielectric-metal (MDM) bus waveguide coupled to two stub resonators. A uniform theoretical model, for both direct and indirect couplings between the two stubs, is established to study spectral features in the plasmonic stub waveguide, and the theoretical results agree well with the finite difference time domain simulations. Adjusting phase difference and coupling strength of the interaction, one can realize the EIT-like phenomena and achieve the required slow light effect. The theoretical results may provide a guideline for the control of light in highly integrated optical circuits.

Plasmon-induced transparency in a single multimode stub resonator.

Abstract: We investigate electromagnetically induced transparency (EIT)-like effect in a metal-dielectric-metal (MDM) waveguide coupled to a single multimode stub resonator. Adjusting the geometrical parameters of the stub resonator, we can realize single or double plasmon-induced transparency (PIT) windows in the plasmonic structure. Moreover, the consistency between analytical results and finite difference time domain (FDTD) simulations reveals that the PIT results from the destructive interference between resonance modes in the stub resonator. Compared with previous EIT-like scheme based on MDM waveguide, the plasmonic system takes the advantages of easy fabrication and compactness. The results may open up avenues for the control of light in highly integrated optical circuits.

Sub-wavelength microwave electric field imaging using Rydberg atoms inside atomic vapor cells

Abstract: We have recently shown that Alkali atoms contained in a vapor cell can serve as a highly accurate standard for microwave electric field strength as well as polarization using the principles of Rydberg atom electromagnetically induced transparency. Here, we show, for the first time, that Rydberg atom electromagnetically induced transparency can be used to image microwave electric fields with unprecedented precision. The spatial resolution of the method is far into the sub-wavelength regime. The electric field resolutions are similar to those we have demonstrated in our prior experiments. Our experimental results agree with finite element calculations of test electric field patterns.

Electromagnetically induced transparency and Autler-Townes splitting in superconducting flux quantum circuits

Abstract: We study the microwave absorption of a driven three-level quantum system, which is realized by a superconducting flux quantum circuit (SFQC), with a magnetic driving field applied to the two upper levels. The interaction between the three-level system and its environment is studied within the Born-Markov approximation, and we take into account the effects of the driving field on the damping rates of the three-level system. We study the linear response of the driven three-level SFQC to a weak probe field. The linear magnetic susceptibility of the SFQC can be changed by both the driving field and the bias magnetic flux. When the bias magnetic flux is at the optimal point, the transition from the ground state to the second-excited state is forbidden and the three-level SFQC has a ladder-type transition. Thus, the SFQC responds to the probe field like natural atoms with ladder-type transitions. However, when the bias magnetic flux deviates from the optimal point, the three-level SFQC has a cyclic transition, thus it responds to the probe field like a combination of natural atoms with ladder-type transitions and natural atoms with $\ensuremath{\Lambda}$-type transitions. In particular, we provide detailed discussions on the conditions for realizing electromagnetically induced transparency and Autler-Townes splitting in three-level SFQCs.

Plasmon induced transparency in a surface plasmon polariton waveguide with a comb line slot and rectangle cavity

Abstract: The phenomenon of electromagnetically induced transparency (EIT) is demonstrated in a surface plasmon polariton waveguide at infrared frequencies. The comb line slot and rectangle cavity are placed inside one of the metallic claddings, and their coupling intensities among them are utilized to obtain bright and dark states. The destructive interference between the bright and dark states leads to an EIT-like transmission spectrum of the waveguide. The induced transparency peak can be manipulated by adjusting the coupling distance between the bright and dark states. Finally, the influence of Joule loss on the EIT-like effect is investigated. It is found that the EIT-like transmission contrast is sensitive to the variation in the metallic damping factor.

Gyromagnetically induced transparency of metasurfaces.

Abstract: We demonstrate that the presence of a (gyro) magnetic substrate can produce an analog of electromagnetically induced transparency in Fano-resonant metamolecules. The simplest implementation of such gyromagnetically induced transparency (GIT) in a metasurface, comprised of an array of resonant antenna pairs placed on a gyromagnetic substrate and illuminated by a normally incident electromagnetic wave, is analyzed. Time reversal and spatial inversion symmetry breaking introduced by the dc magnetization makes metamolecules bianisotropic. This causes Fano interference between the otherwise uncoupled symmetric and antisymmetric resonances of the metamolecules giving rise to a sharp transmission peak through the otherwise reflective metasurface. We show that, for an oblique wave incidence, one-way GIT can be achieved by the combination of spatial dispersion and gyromagnetic effect. These theoretically predicted phenomena pave the way to nonreciprocal switches and isolators that can be dynamically controlled by electric currents.

Electromagnetically Induced Transparency-Like Transmission in a Compact Side-Coupled T-Shaped Resonator

Abstract: A plasmonic bus waveguide with a side-coupled T-shaped (TS) or a reverse T-shaped (RTS) resonator consisting of a parallel and a perpendicular cavities is proposed. The compact configuration could serve as a wavelength demultiplexing device as a forbidden band is achieved based on the symmetric distribution of resonators. By shifting one cavity away from the center of the resonator, the system exhibits electromagnetically induced transparency (EIT) like transmission at the wavelength of the former forbidden band. The electromagnetic responses of the structure could be handled with certain flexibility by changing the asymmetric behavior of the TS or RTS resonator. Similar characteristics for two proposed structures could be obtained except for the center wavelength that is determined by the two cavities in the RTS resonator or by the cavity parallel to the bus waveguide in the TS resonator.

Dual-mode electromagnetically induced transparency and slow light in a terahertz metamaterial

Abstract: In this Letter, we construct a metamaterial with dual-mode electromagnetically induced transparency (EIT)-like behavior by introducing "bright atoms," "quasi-dark atoms," and "dark atoms" simultaneously. The dual-mode EIT-like behavior has been demonstrated both experimentally and theoretically in terahertz (THz) regime. At two EIT-like modes, slow light is also observed as two time-delayed wave packets, and the effective group refractive index can reach 10(2). Furthermore, stable dual-mode EIT-like behavior is verified in this metamaterial for a wide range of oblique incident angles. Our work provides a design approach to mimic dual-mode EIT, and such an approach may achieve potential applications on miniaturized and versatile THz devices.

Coherent perfect absorption, transmission, and synthesis in a double-cavity optomechanical system

Abstract: We study a double-cavity optomechanical system in which a movable mirror with perfect reflection is inserted between two fixed mirrors with partial transmission. This optomechanical system is driven from both fixed end mirrors in a symmetric scheme by two strong coupling fields and two weak probe fields. We find that three interesting phenomena: coherent perfect absorption (CPA), coherent perfect transmission (CPT), and coherent perfect synthesis (CPS) can be attained within different parameter regimes. That is, we can make two input probe fields totally absorbed by the movable mirror without yielding any energy output from either end mirror (CPA); make an input probe field transmitted from one end mirror to the other end mirror without suffering any energy loss in the two cavities (CPT); make two input probe fields synthesized into one output probe field after undergoing either a perfect transmission or a perfect reflection (CPS). These interesting phenomena originate from the efficient hybrid coupling of optical and mechanical modes and may be all-optically controlled to realize novel photonic devices in quantum information networks.

Atom Based Vector Microwave Electrometry Using Rubidium Rydberg Atoms in a Vapor Cell

Abstract: We demonstrate our recent results on microwave field strength and polarization electrometry using a bright resonance prepared within an electromagnetically induced transparency window in a Rubidium vapor cell.

Photon pairs with coherence time exceeding 1 μs

Abstract: The generation of nonclassical photon pairs with a long coherence time is key for applications that range from fundamental to quantum communication and metrology. Spontaneous four-wave mixing with electromagnetically induced transparency has been demonstrated as one of the most efficient methods; however, narrowing the bandwidth and producing photon pairs with a temporal length beyond 1 μs remains a technical challenge due to noise considerations and the need for cold atoms with a high optical depth (OD). In this work, we demonstrate the generation of narrowband photon pairs with a controllable coherence time up to 1.72 μs in a laser-cooled atomic ensemble with an OD as high as 130. At such a high OD, we find that the pump laser field spatial profile has a significant effect on the time–frequency entangled two-photon waveform. We also confirm the quantum particle nature of heralded narrowband single photons generated from this source.

Electromagnetically induced transparency in an entangled medium.

Abstract: We theoretically investigate light propagation and electromagnetically induced transparency (EIT) in a quasi one-dimensional gas in which atoms interact strongly via exchange interactions. We focus on the case in which the gas is initially prepared in a many-body state that contains a single excitation and conduct a detailed study of the absorptive and dispersive properties of such a medium. This scenario is achieved in interacting gases of Rydberg atoms with two relevant S-states that are coupled through exchange. Of particular interest is the case in which the medium is prepared in an entangled spinwave state. This, in conjunction with the exchange interaction, gives rise to a non-local susceptibilty which --- in comparison to conventional Rydberg EIT --- qualitatively alters the absorption and propagation of weak probe light, leading to non-local propagation and enhanced absorption.

Analogue of electromagnetically induced transparency in integrated plasmonics with radiative and subradiant resonators.

Abstract: We propose the use of radiative and subradiant resonators coupled to a metal-insulator-metal waveguide to represent the three-level energy diagram in conventional atomic systems and demonstrate a new realization of on-chip plasmonic analogue of electromagnetically-induced transparency (EIT) in integrated plasmonics. The radiative resonator is achieved with the help of aperture-coupling while evanescent coupling is relied for the subradiant resonator. Numerical simulation results demonstrate well-pronounced intermediate transmission peak through the bus waveguide and also show that the EIT effect can be easily controlled by the relative position of the two Fabry-Perot resonators.

Superradiance Lattice

Abstract: We show that the timed Dicke states of a collection of three-level atoms can form a tight-binding lattice in momentum space This lattice, coined the superradiance lattice (SL), can be constructed based on electromagnetically induced transparency (EIT) For a one-dimensional SL, we need the coupling field of the EIT system to be a standing wave The detuning between the two components of the standing wave introduces an effective uniform force in momentum space The quantum lattice dynamics, such as Bloch oscillations, Wannier-Stark ladders, Bloch band collapsing and dynamic localization can be observed in the SL The two-dimensional SL provides a flexible platform for Dirac physics in graphene The SL can be extended to three and higher dimensions where no analogous real space lattices exist with new physics waiting to be explored

Magnetically coupled electromagnetically induced transparency analogy of dielectric metamaterial

Abstract: In this manuscript, we experimentally demonstrate magnetically coupled electromagnetically induced transparency (EIT) analogy effect inside dielectric metamaterial. In contrast to previous studies employed different metallic topological microstructures to introduce dissipation loss change, barium strontium titanate, and calcium titanate (CaTiO3) are chosen as the bright and dark EIT resonators, respectively, due to their different intrinsic dielectric loss. Under incident magnetic field excitation, dielectric metamaterial exhibits an EIT-type transparency window around 8.9 GHz, which is accompanied by abrupt change of transmission phase. Numerical calculations show good agreement with experiment spectra and reveal remarkably increased group index, indicating potential application in slow light.