Showing papers on "Electromagnetically induced transparency published in 2018"

Recent Advances in Resonant Waveguide Gratings

Abstract: Resonant waveguide gratings (RWGs), also known as guided mode resonant (GMR) gratings or waveguide-mode resonant gratings, are dielectric structures where these resonant diffractive elements benefit from lateral leaky guided modes from UV to microwave frequencies in many different configurations. A broad range of optical effects are obtained using RWGs such as waveguide coupling, filtering, focusing, field enhancement and nonlinear effects, magneto-optical Kerr effect, or electromagnetically induced transparency. Thanks to their high degree of optical tunability (wavelength, phase, polarization, intensity) and the variety of fabrication processes and materials available, RWGs have been implemented in a broad scope of applications in research and industry: refractive index and fluorescence biosensors, solar cells and photodetectors, signal processing, polarizers and wave plates, spectrometers, active tunable filters, mirrors for lasers and optical security features. The aim of this review is to discuss the latest developments in the field including numerical modeling, manufacturing, the physics, and applications of RWGs. Scientists and engineers interested in using RWGs for their application will also find links to the standard tools and references in modeling and fabrication according to their needs.

Highly Efficient Coherent Optical Memory Based on Electromagnetically Induced Transparency

Abstract: Quantum memory is an important component in the long-distance quantum communication based on the quantum repeater protocol. To outperform the direct transmission of photons with quantum repeaters, it is crucial to develop quantum memories with high fidelity, high efficiency and a long storage time. Here, we achieve a storage efficiency of 92.0 (1.5)% for a coherent optical memory based on the electromagnetically induced transparency scheme in optically dense cold atomic media. We also obtain a useful time-bandwidth product of 1200, considering only storage where the retrieval efficiency remains above 50%. Both are the best record to date in all kinds of schemes for the realization of optical memory. Our work significantly advances the pursuit of a high-performance optical memory and should have important applications in quantum information science.

Enhanced high-harmonic generation from an all-dielectric metasurface

Abstract: The recent observation of high-harmonic generation from solids creates a new possibility for engineering fundamental strong-field processes by patterning the solid target with subwavelength nanostructures. All-dielectric metasurfaces exhibit high damage thresholds and strong enhancement of the driving field, making them attractive platforms to control high harmonics and other high-field processes at the nanoscale. Here we report enhanced non-perturbative high-harmonic emission from a Fano-resonant Si metasurface that possesses a classical analogue of electromagnetically induced transparency. The harmonic emission is enhanced by more than two orders of magnitude compared to unpatterned samples. The enhanced high harmonics are highly anisotropic with respect to the excitation polarization and are selective by the excitation wavelength due to its resonant features. By combining nanofabrication technology and ultrafast strong-field physics, our work paves the way for the design of new compact ultrafast photonic devices that operate under high intensities and at short wavelengths.

Superconducting cavity electro-optics: A platform for coherent photon conversion between superconducting and photonic circuits.

Abstract: Leveraging the quantum information-processing ability of superconducting circuits and long-distance distribution ability of optical photons promises the realization of complex and large-scale quantum networks. In such a scheme, a coherent and efficient quantum transducer between superconducting and photonic circuits is critical. However, this quantum transducer is still challenging because the use of intermediate excitations in current schemes introduces extra noise and limits bandwidth. We realize direct and coherent transduction between superconducting and photonic circuits based on the triple-resonance electro-optic principle, with integrated devices incorporating both superconducting and optical cavities on the same chip. Electromagnetically induced transparency is observed, indicating the coherent interaction between microwave and optical photons. Internal conversion efficiency of 25.9 ± 0.3% has been achieved, with 2.05 ± 0.04% total efficiency. Superconducting cavity electro-optics offers broad transduction bandwidth and high scalability and represents a significant step toward integrated hybrid quantum circuits and distributed quantum computation.

Electrically tunable slow light using graphene metamaterials

Abstract: Metamaterials with classical analogues of electromagnetically induced transparency open new avenues in photonics for realizing smaller, more efficient slow light devices without quantum approaches. However, most of the metamaterial-based slow light devices are passive, which limits their practical applications. Here, by combining diatomic metamaterials with a gated single-layer graphene, we demonstrate that the group delay of terahertz light can be dynamically controlled under a small gate voltage. Using a two coupled harmonic oscillators model, we show that this active control of group delay is made possible by an effective control of the dissipative loss of the radiative dark resonator by varying the graphene’s optical conductivity. Our work may provide opportunities in the design of various applications such as compact slow light devices and ultrasensitive sensors and switches.

Electromagnetically induced transparency control in terahertz metasurfaces based on bright-bright mode coupling

Abstract: We demonstrate a classical analog of electromagnetically induced transparency (EIT) in a highly flexible planar terahertz metamaterial (MM) comprised of three-gap split-ring resonators. The keys to achieve EIT in this system are the frequency detuning and hybridization processes between two bright modes coexisting in the same unit cell as opposed to bright-dark modes. We present experimental verification of two bright modes coupling for a terahertz EIT-MM in the context of numerical results and theoretical analysis based on a coupled Lorentz oscillator model. In addition, a hybrid variation of the EIT-MM is proposed and implemented numerically to dynamically tune the EIT window by incorporating photosensitive silicon pads in the split gap region of the resonators. As a result, this hybrid MM enables the active optical control of a transition from the on state (EIT mode) to the off state (dipole mode).

Fundamentals and applications of optomechanically induced transparency

Abstract: Cavity optomechanical systems have been shown to exhibit an analogon to atomic electromagnetically induced transparency that a transmission window for the propagation of the probe field is induced by a strong control field when the resonance condition is met. Sharp transmission features controlled by the control laser beam enable many applications ranging from force sensors to quantum communication. In recent years, there has been significant progress in both theoretical and experimental studies of this phenomenon, driven by the development of nanophotonics as well as the improvement of nano-fabrication techniques. Optomechanically induced transparency has been found to manifest in numerous different physical mechanisms, e.g., nonlinear optomechanically induced transparency, double optomechanically induced transparency, parity-time symmetric optomechanically induced transparency, and optomechanically induced transparency in various hybrid optomechanical systems, etc. These results offer a pathway towards an integrated quantum optomechanical memory, show the utility of these chip-scale optomechanical systems for optical buffering, amplification, and filtering of microwave-over-optical signals, and may be applicable to modern optical networks and future quantum networks. Here, we systematically review the latest research progress on the fundamentals and applications of optomechanically induced transparency. Perspectives and opportunities on future developments are also provided by focusing on several promising topics.

Active Control of Electromagnetically Induced Transparency in a Terahertz Metamaterial Array with Graphene for Continuous Resonance Frequency Tuning

Abstract: Optoelectronic terahertz modulators, operated by actively tuning metamaterial, plasmonic resonator structures, have helped to unlock a myriad of terahertz applications, ranging from spectroscopy and imaging to communications At the same time, due to the inherently versatile dispersion properties of metamaterials, they offer unique platforms for studying intriguing phenomena such as negative refractive index and slow light Active resonance frequency tuning of a metamaterial working in the terahertz regime is achieved by integrating metal-coupled resonator arrays with electrically tunable graphene This metamaterial device exploits coupled plasmonic resonators to exhibit an electromagnetically induced transparency analog, resulting in the splitting of the resonance into coupled hybrid optical modes By variably dampening one of the resonators using graphene, the coupling condition is electrically modulated and continuous tuning of the metamaterial resonance frequency is achieved This device, operating at room temperature, can readily be implemented as a fast, optoelectronic, tunable band pass/reject filter with a tuning range of ≈100 GHz operating at 15 THz The reconfigurable dispersion properties of this device can also be implemented for modulation of the group delay for slow light applications

Omnidirectional tunable terahertz analog of electromagnetically induced transparency realized by isotropic vanadium dioxide metasurfaces

Abstract: We present an isotropic active analog of electromagnetically induced transparency through conductivity tuning of vanadium dioxide at terahertz frequencies. The unit cell of the designed metasurface consists of metallic split ring resonators and a metallic cross, which have identical resonance frequencies for the excitable lowest order modes but very different linewidths. By integrating vanadium dioxide into the bottom of the metasurface, an obvious tuning of the transparency window occurs under different conductivities. Calculated results show that resonant transmission frequency of the electromagnetically induced transparency remains stable with respect to the polarization and incident angle of electromagnetic waves.

Enhancement of electromagnetically induced transparency in metamaterials using long range coupling mediated by a hyperbolic material

Abstract: Near-field coupling is a fundamental physical effect, which plays an important role in the establishment of classical analog of electromagnetically induced transparency (EIT). However, in a normal environment the coupling length between the bright and dark artificial atoms is very short and far less than one wavelength, owing to the exponentially decaying property of near fields. In this work, we report the realization of a long range EIT, by using a hyperbolic metamaterial (HMM) which can convert the near fields into high-k propagating waves to overcome the problem of weak coupling at long distance. Both simulation and experiment show that the coupling length can be enhanced by nearly two orders of magnitude with the aid of a HMM. This long range EIT might be very useful in a variety of applications including sensors, detectors, switch, long-range energy transfer, etc.

Giant enhancement of Faraday rotation due to electromagnetically induced transparency in all-dielectric magneto-optical metasurfaces.

Abstract: In this Letter we introduce a new class of Fano-resonant all-dielectric metasurfaces for enhanced, high figure of merit magneto-optical response. The metasurfaces are formed by an array of magneto-optical bismuth-substituted yttrium iron garnet nano-disks embedded into a low-index matrix. The strong field enhancement in the magneto-optical disks, which results in over an order of magnitude enhancement of Faraday rotation, is achieved by engineering two (electric and magnetic) resonances. It is shown that while enhancement of rotation also takes place for spectrally detuned resonances, the resonant excitation inevitably results in stronger reflection and low figure of merit of the device. We demonstrate that this can be circumvented by overlapping electric and magnetic resonances of the nanodisks, yielding a sharp electromagnetically induced transparency peak in the transmission spectrum, which is accompanied by gigantic Faraday rotation. Our results show that one can simultaneously obtain a large Faraday rotation enhancement along with almost 100% transmittance in an all-dielectric metasurface as thin as 300 nm. A simple analytical model based on coupled-mode theory is introduced to explain the effects observed in first-principle finite element method simulations.

Fiber-coupled vapor cell for a portable Rydberg atom-based radio frequency electric field sensor.

Abstract: We demonstrate a movable, Rydberg atom-based radio frequency (RF) electric (E) field probe. The technique is based on electromagnetically induced transparency and Autler–Townes splitting. Two fibers attached to a 10 mm cubic Cs133 vapor cell are used to couple counter-propagating probe and control lasers through the cell. This all-dielectric fiber-coupled sensor can be moved from the optics table to locations more suitable for RF (gigahertz to sub-terahertz) E-field measurements and calibrations.

Flexibly tunable high-quality-factor induced transparency in plasmonic systems.

Abstract: The quality (Q) factor and tunability of electromagnetically induced transparency (EIT)-like effect in plasmonic systems are restrained by the intrinsic loss and weak adjustability of metals, limiting the performance of the devices including optical sensor and storage. Exploring new schemes to realize the high Q-factor and tunable EIT-like effect is particularly significant in plasmonic systems. Here, we present an ultrahigh Q-factor and flexibly tunable EIT-like response in a novel plasmonic system. The results illustrate that the induced transparency distinctly appears when surface plasmon polaritons excited on the metal satisfy the wavevector matching condition with the guided mode in the high-refractive index (HRI) layer. The Q factor of the EIT-like spectrum can exceed 2000, which is remarkable compared to that of other plasmonic systems such as plasmonic metamaterials and waveguides. The position and lineshape of EIT-like spectrum are strongly dependent on the geometrical parameters. An EIT pair is generated in the splitting absorption spectra, which can be easily controlled by adjusting the incident angle of light. Especially, we achieve the dynamical tunability of EIT-like spectrum by changing the Fermi level of graphene inserted in the system. Our results will open a new avenue toward the plasmonic sensing, spectral shaping and switching.

Superconducting cavity electro-optics: a platform for coherent photon conversion between superconducting and photonic circuits

Abstract: Leveraging the quantum information processing ability of superconducting circuits and long-distance distribution ability of optical photons promises the realization of complex and large-scale quantum networks. In such a scheme, a coherent and efficient quantum transducer between superconducting and photonic circuits is critical. However, such quantum transducer is still challenging since the use of intermediate excitations in current schemes introduces extra noise and limits bandwidth. Here we realize direct and coherent transduction between superconducting and photonic circuits based on triple-resonance electro-optics principle, with integrated devices incorporating both superconducting and optical cavities on the same chip. Electromagnetically induced transparency is observed, indicating the coherent interaction between microwave and optical photons. Internal conversion efficiency of 25.9\pm0.3\% has been achieved, with 2.05\pm0.04\% total efficiency. Superconducting cavity electro-optics offers broad transduction bandwidth and high scalability, and represents a significant step towards the integrated hybrid quantum circuits and distributed quantum computation.

Radio-over-fiber using an optical antenna based on Rydberg states of atoms

Abstract: We provide an experimental demonstration of a direct fiber-optic link for RF transmission (“radio-over-fiber”) using a sensitive optical antenna based on a rubidium vapor cell. The scheme relies on measuring the transmission of laser light at an electromagnetically induced transparency resonance that involves highly excited Rydberg states. By dressing pairs of Rydberg states using microwave fields that act as local oscillators, we encoded RF signals in the optical frequency domain. The light carrying the information is linked via a virtually lossless optical fiber to a photodetector where the signal is retrieved. We demonstrate a signal bandwidth in excess of 1 MHz limited by the available coupling laser power and atomic optical density. Our sensitive, non-metallic and readily scalable optical antenna for microwaves allows extremely low-levels of optical power (∼1 μW) throughput in the fiber-optic link. It offers a promising future platform for emerging wireless network infrastructures.

Analog of electromagnetically induced transparency in an E-shaped all-dielectric metasurface based on toroidal dipolar response

Abstract: An analog of electromagnetically induced transparency (EIT) in an asymmetric E-shaped all-dielectric metasurface was proposed and numerically demonstrated in the near infrared spectral region. The E-shaped metasurface supports a strong toroidal dipolar resonance with high quality (Q) factor, which is verified by decomposed scattered powers for multipole moments using a Cartesian coordinate system. A high transmission EIT-like optical response was achieved, and clearly interpreted by the destructive interference between the dark toroidal dipolar moment and bright magnetic dipolar mode through the asymmetric metasurface. The bandwidth of the transparency window can be easily designed by changing the asymmetric parameter of the structure. The proposed E-shaped all-dielectric metasurface gives a new way to realize toroidal dipolar response and has potential applications in bio-chemical sensing, narrowband filters, optical modulations, and slow light based devices.

Nanoimaging and Control of Molecular Vibrations through Electromagnetically Induced Scattering Reaching the Strong Coupling Regime.

Abstract: Optical resonators can enhance light-matter interaction, modify intrinsic molecular properties such as radiative emission rates, and create new molecule-photon hybrid quantum states. To date, corresponding implementations are based on electronic transitions in the visible spectral region with large transition dipoles yet hampered by fast femtosecond electronic dephasing. In contrast, coupling molecular vibrations with their weaker dipoles to infrared optical resonators has been less explored, despite long-lived coherences with 2 orders of magnitude longer dephasing times. Here, we achieve excitation of molecular vibrations through configurable optical interactions of a nanotip with an infrared resonant nanowire that supports tunable bright and nonradiative dark modes. The resulting antenna-vibrational coupling up to 47 ± 5 cm-1 exceeds the intrinsic dephasing rate of the molecular vibration, leading to hybridization and mode splitting. We observe nanotip-induced quantum interference of vibrational excitation pathways in spectroscopic nanoimaging, which we model classically as plasmonic electromagnetically induced scattering as the phase-controlled extension of the classical analogue of electromagnetically induced transparency and absorption. Our results present a new regime of IR spectroscopy for applications of vibrational coherence from quantum computing to optical control of chemical reactions.

Quantum interference in second-harmonic generation from monolayer WSe2

Abstract: A hallmark of wave-matter duality is the emergence of quantum-interference phenomena when an electronic transition follows different trajectories. Such interference results in asymmetric absorption lines such as Fano resonances, and gives rise to secondary effects like electromagnetically induced transparency (EIT) when multiple optical transitions are pumped. Few solid-state systems show quantum interference and EIT, with quantum-well intersubband transitions in the IR offering the most promising avenue to date to devices exploiting optical gain without inversion. Quantum interference is usually hampered by inhomogeneous broadening of electronic transitions, making it challenging to achieve in solids at visible wavelengths and elevated temperatures. However, disorder effects can be mitigated by raising the oscillator strength of atom-like electronic transitions - excitons - which arise in monolayers of transition-metal dichalcogenides (TMDCs). Quantum interference, probed by second-harmonic generation (SHG), emerges in monolayer WSe2, without a cavity, splitting the SHG spectrum. The splitting exhibits spectral anticrossing behaviour, and is related to the number of Rabi flops the strongly driven system undergoes. The SHG power-law exponent deviates strongly from the canonical value of 2, showing a Fano-like wavelength dependence which is retained at room temperature. The work opens opportunities in solid-state quantum-nonlinear optics for optical mixing, gain without inversion and quantum-information processing.

Loss-induced transparency in optomechanics.

Abstract: We study optomechanically induced transparency (OMIT) in a compound system consisting of coupled optical resonators and a mechanical mode, focusing on the unconventional role of loss. We find that optical transparency can emerge at the otherwise strongly absorptive regime in the OMIT spectrum, by using an external nanotip to enhance the optical loss. In particular, loss-induced revival of optical transparency and the associated slow-to-fast light switch can be identified in the vicinity of an exceptional point. These results open up a counterintuitive way to engineer micro-mechanical devices with tunable losses for e.g., coherent optical switch and communications.

Exchange of optical vortices using an electromagnetically-induced-transparency-based four-wave-mixing setup

Abstract: We propose a scheme to exchange optical vortices of slow light using the phenomenon of electromagnetically induced transparency in a four-level double-$\mathrm{\ensuremath{\Lambda}}$ atom-light coupling scheme illuminated by a pair of probe fields as well as two control fields of larger intensity. We study the light-matter interaction under the situation where one control field carries an optical vortex, and another control field has no vortex. We show that the orbital angular momentum (OAM) of the vortex control beam can be transferred to a generated probe field through a four-wave-mixing process and without switching on and off of the control fields. Such a mechanism of OAM transfer is much simpler than in a double-tripod scheme in which the exchange of vortices is possible only when two control fields carry optical vortices of opposite helicity. The losses appearing during such OAM exchange are then calculated. It is found that the one-photon detuning plays an important role in minimizing the losses. An approximate analytical expression is obtained for the optimal one-photon detuning for which the losses are minimum while the intensity of generated probe field is maximum. The influence of phase mismatch on the exchange of optical vortices is also investigated. We show that in presence of phase mismatch the exchange of optical vortices can still be efficient.

A quantum-based power standard: Using Rydberg atoms for a SI-traceable radio-frequency power measurement technique in rectangular waveguides

Abstract: In this work, we demonstrate an approach for determining radio-frequency (RF) power using electromagnetically induced transparency (EIT) in a Rydberg atomic vapor. This is accomplished by placing alkali atomic vapor in a rectangular waveguide and measuring the electric (E) field strength (utilizing EIT and Autler-Townes splitting) for a wave propagating down the waveguide. The RF power carried by the wave is then related to this measured E-field, which leads to a direct International System of Units measurement of RF power. To demonstrate this approach, we first measure the field distribution of the fundamental mode in the waveguide and then determine the power carried by the wave at both 19.629 GHz and 26.526 GHz from the measured E-field. We show comparisons between the RF power obtained with this technique and those obtained with a conventional power meter.

Independently tunable dual-spectral electromagnetically induced transparency in a terahertz metal-graphene metamaterial

Abstract: We theoretically investigate the interaction between the conductive graphene layer with the dual-spectral electromagnetically induced transparency (EIT) metamaterial and achieve independent amplitude modulation of the transmission peaks in the terahertz (THz) regime. The dual-spectral EIT resonance results from the strong near field coupling effects between the bright cut wire resonator in the middle and two dark double-split ring resonators on the two sides. By integrating monolayer graphene under the dark mode resonators, the two transmission peaks of the EIT resonance can exhibit independent amplitude modulation via the shifting of the Fermi level of the corresponding graphene layer. The physical mechanism of the modulation can be attributed to the variation of damping factors of the dark mode resonators arising from the tunable conductivity of graphene. This work shows great prospects in designing multiple-spectral THz functional devices with highly flexible tunability and implies promising applications in multi-channel selective switching, modulation and slow light.

Liquid-crystal-integrated metadevice: towards active multifunctional terahertz wave manipulations.

Abstract: Active terahertz elements with multifunction are highly expected in security screening, nondestructive evaluation, and wireless communications. Here, we propose an innovative terahertz metadevice that exhibits distinguishing functions for transmitted and reflected waves. The device is composed of a thin liquid crystal layer sandwiched by Au comb electrodes and a dual-ring resonator array. For transmission mode, the metadevice manifests the electromagnetically induced transparency analog. For reflection mode, it works as a perfect absorber. The comb electrodes actuate the in-plane switching of liquid crystals, making the metadevice actively tuned. 60 GHz frequency tuning of an electromagnetically induced transparency analog and 15% modulation depth of the absorption are demonstrated. Such modulations can be realized in the millisecond scale. The in-plane switching driving mode avoids the electrode connections among separate resonators, thus freeing the design of the metadevice. The proposed work may pave a bright road towards various active multifunctional terahertz apparatuses.

A polarization independent electromagnetically induced transparency-like metamaterial with large group delay and delay-bandwidth product

Abstract: In this study, a classical analogue of electromagnetically induced transparency (EIT) that is completely independent of the polarization direction of the incident waves is numerically and experimentally demonstrated. The unit cell of the employed planar symmetric metamaterial structure consists of one square ring resonator and four split ring resonators (SRRs). Two different designs are implemented in order to achieve a narrow-band and wide-band EIT-like response. In the unit cell design, a square ring resonator is shown to serve as a bright resonator, whereas the SRRs behave as a quasi-dark resonator, for the narrow-band (0.55 GHz full-width at half-maximum bandwidth around 5 GHz) and wide-band (1.35 GHz full-width at half-maximum bandwidth around 5.7 GHz) EIT-like metamaterials. The observed EIT-like transmission phenomenon is theoretically explained by a coupled-oscillator model. Within the transmission window, steep changes of the phase result in high group delays and the delay-bandwidth products reach 0.45 for the wide-band EIT-like metamaterial. Furthermore, it has been demonstrated that the bandwidth and group delay of the EIT-like band can be controlled by changing the incidence angle of electromagnetic waves. These features enable the proposed metamaterials to achieve potential applications in filtering, switching, data storing, and sensing.

Rayleigh Waves in Phononic Crystal Made of Multilayered Pillars: Confined Modes, Fano Resonances, and Acoustically Induced Transparency

Abstract: We present a design of phononic crystal based on pillars distributed on a substrate surface in which each pillar is constructed by a periodic stacking of PMMA and silicon layers. The pillar behaves like a one-dimensional phononic crystal which allows the creation of band gaps that prohibits wave propagation along the pillar. Thanks to this property, we show that confined modes are produced at the pillar-substrate interface which couples with surface acoustic waves (SAW) and causes their attenuation. Furthermore, by tailoring a defect inside the phononic pillar, we reveal the possibility to create confined cavity modes inside the band gap which can strongly couple with SAW. The cavity modes can be excited by SAW and the coupling produces sharp SAW transmissions. Additionally, we demonstrate that the coupling between the cavity modes and the confined modes at the pillar-substrate interface can give rise to a Fano-like resonance. We also evidence the possibility of generating an acoustic analogue of electromagnetically induced transparency for SAW with high transmission in a narrow bandwidth. The system presents perspectives for the design of high quality-factor phononic excitation for optomechanic devices and phonon circuits based on SAW manipulation.

Slowing down light using terahertz semiconductor metamaterial for dual-band thermally tunable modulator applications.

Abstract: Compared to the neighboring infrared and microwave regions, the terahertz regime is still in need of fundamental technological advances. We have designed a terahertz (THz) semiconductor metamaterial (MM) waveguide system, which exhibits a significant slow-light effect, based on a classical electromagnetically induced transparency phenomenon. The potential of MMs for THz radiation originates from a resonant electromagnetic response that can be tailored for specific applications. By appropriately adjusting the distance between the two radiative and nonradiative modes, a flat band corresponding to a nearly constant group index (of the order of 4924) in the THz regime can be achieved. Finite-difference time-domain simulations show that the incident pulse can be slowed down. The proposed device from a paucity of naturally occurring materials has useful applications in electronic or photonic properties at terahertz frequencies. This proposed compact configuration may find potential applications in plasmonic slow-light systems, optical buffers, and thermal and electromagnetic modulating applications and temperature sensors.

Interaction of light with planar lattices of atoms: Reflection, transmission, and cooperative magnetometry

Abstract: We study strong, light-mediated, resonant dipole-dipole interactions in two-dimensional planar lattices of cold atoms. We provide a detailed analysis for the description of the dipolar point emitter lattice plane as a “superatom” whose response is similar to electromagnetically induced transparency but which exhibits an ultranarrow collective size-dependent subradiant resonance linewidth. The superatom model provides intuitively simple descriptions for the spectral response of the array, including the complete reflection, full transmission, narrow Fano resonances, and asymptotic expressions for the resonance linewidths of the collective eigenmodes. We propose a protocol to transfer almost the entire radiative excitation to a single correlated subradiant eigenmode in a lattice and show that the medium obtained by stacked lattice arrays can form a cooperative magnetometer. Such a magnetometer utilizes similar principles as magnetometers based on the electromagnetically induced transparency. The accuracy of the cooperative magnetometer, however, is not limited by the single-atom resonance linewidth but the much narrower collective linewidth that results from the strong dipole-dipole interactions.