Array Of Coupled Cavities Research Articles

Enhancing the charging performance of quantum batteries with the work medium of an entangled coupled-cavity array

Enhancing the charging performance of quantum batteries with the work medium of an entangled coupled-cavity array

Thermo-optic effect induced tunable phase controlled propagation of solitons in a Jaynes-Cummings-Hubbard model

The manipulation of light propagation has garnered significant attention in discrete periodic photon structures. In this study, we investigate the impact of an adjustable phase on soliton behavior within a one-dimensional (1D) coupled cavity array. Each cavity is doped with two-level qubits, and the system can be effectively described by a Jaynes-Cummings-Hubbard model (JC-Hubbard model). By numerically exploring the photonic phase, we reveal that it introduces an additional degree of flexibility in controlling soliton propagation. This flexibility encompasses dispersion relations, propagation direction, transverse velocity, and stability conditions. We observe that soliton styles transition with changes in the tunneling phase. At a phase of 0, solitons form due to the delicate balance between spatial dispersion and system nonlinearity. When the phase increases to π/2, solitons vanish because spatial dispersion is significantly suppressed. The underlying theory explains this suppression, which arises from the opposite phase ±θ. Interestingly, standard temporal solitons emerge in the discrete periodic cavity array. Our investigation has broader applicability extending to various discrete structures, encompassing but not limited to waveguide arrays and optomechanical cavity arrays.

Polariton creation in coupled cavity arrays with spectrally disordered emitters

Integrated photonics has been a promising platform for analog quantum simulation of condensed matter phenomena in strongly correlated systems. To that end, we explore the implementation of all-photonic quantum simulators in coupled cavity arrays with integrated ensembles of spectrally disordered emitters. Our model is reflective of color center ensembles integrated into photonic crystal cavity arrays. Using the Quantum Master equation and the Effective Hamiltonian approaches, we study energy band formation and wavefunction properties in the open quantum Tavis–Cummings–Hubbard framework. We find conditions for polariton creation and (de)localization under experimentally relevant values of disorder in emitter frequencies, cavity resonance frequencies, and emitter-cavity coupling rates. To quantify these properties, we introduce two metrics, the polaritonic and nodal participation ratios, that characterize the light-matter hybridization and the node delocalization of the wavefunction, respectively. These new metrics combined with the Effective Hamiltonian approach prove to be a powerful toolbox for cavity quantum electrodynamical engineering of solid-state systems.

Topological laser on square lattice with gain–loss-induced higher-order corner modes

We investigate the higher-order topological laser in the two-dimensional (2D) coupled-cavity array. By adding staggered on-site gain and loss to the 2D Hermitian array with a trivial phase, the system will emerge degenerate topological corner modes, which are protected by bulk band gap. For such a non-Hermitian model, by adjusting the parameters of the system and introducing the pumping into the cavity at the corner, a single-mode lasing with topological protection emerges. Furthermore, single-mode lasing exists over a wide range of pumping strengths. No matter where the cavity is initially stimulated, after enough time evolution, all the cavities belonging to the topological corner mode can emit a stable laser.

Non-Hermitian skin effect induced by on-site gain and loss in the optically coupled cavity array

The introduction of non-Hermiticity into topological systems has led to a series of novel physical phenomena and produced application prospects. Here, we combine non-Hermitian and topological photonic systems based on a one-dimensional extended Su-Schrieffer-Heeger (SSH) model, which is composed of the optically coupled cavity array. We found that single on-site gain and loss do not induce the non-Hermitian skin effect (NHSE) in this model. Once the complex next-nearest-neighbor coupling is introduced, which is similar to asymmetric coupling, NHSE exists in the system. Adjusting the parameters of the system, we noted that the behavior of in-gap topological edge modes depends on the competition between non-Hermiticity and band topology. NHSE is featured with two edge modes localized at one end of the array, whereas the latter is characterized by two edge modes distributed at the two ends of the array. In addition, we reveal the condition that a system with gain and loss produces the non-Hermitian skin effect. Our research enriches the integration of non-Hermitian and topological photonics.

Enhancing strength and range of atom-atom interaction in a coupled-cavity array via parametric drives

Enhancing strength and range of atom-atom interaction in a coupled-cavity array via parametric drives

Realizing tight-binding Hamiltonians using site-controlled coupled cavity arrays

Analog quantum simulators rely on programmable and scalable quantum devices to emulate Hamiltonians describing various physical phenomenon. Photonic coupled cavity arrays are a promising alternative platform for realizing such simulators, due to their potential for scalability, small size, and high-temperature operability. However, programmability and nonlinearity in photonic cavities remain outstanding challenges. Here, using a silicon photonic coupled cavity array made up of 8 high quality factor (Q up to, sim 7.1times {10}^{4}) resonators and equipped with specially designed thermo-optic island heaters for independent control of cavities, we demonstrate a programmable photonic cavity array in the telecom regime, implementing tight-binding Hamiltonians with access to the full eigenenergy spectrum. We report a sim 50% reduction in the thermal crosstalk between neighboring sites of the cavity array compared to traditional heaters, and then present a control scheme to program the cavity array to a given tight-binding Hamiltonian. The ability to independently program high-Q photonic cavities, along with the compatibility of silicon photonics to high volume manufacturing opens new opportunities for scalable quantum simulation using telecom regime infrared photons.

Photonic topological insulators induced by non-Hermitian disorders in a coupled-cavity array

Recent studies of disorder or non-Hermiticity induced topological insulators inject new ingredients for engineering topological matter. Here, we consider the effect of purely non-Hermitian disorders, a combination of these two ingredients, in a 1D coupled-cavity array with disordered gain and loss. Topological photonic states can be induced by increasing gain-loss disorder strength with topological invariants carried by localized states in the complex bulk spectra. The system showcases rich phase diagrams and distinct topological states from Hermitian disorders. The non-Hermitian critical behavior is characterized by the biorthogonal localization length of zero-energy edge modes, which diverges at the critical transition point and establishes the bulk-edge correspondence. Furthermore, we show that the bulk topology may be experimentally accessed by measuring the biorthogonal chiral displacement, which can be extracted from a proper Ramsey interferometer that works in both clean and disordered regions. The proposed coupled-cavity photonic setup relies on techniques that have been experimentally demonstrated and, thus, provides a feasible route toward exploring such non-Hermitian disorder driven topological insulators.

Generation of triple-entanglement in second-order optical topological kagome structure

The combination of topological photonics and quantum optics has promising applications. In previous works, the role of the edge states of conventional topological optical structure in the coherent coupling between atoms has been discussed. Besides the optimistic results, we find that if the coupling coefficient between the atom and element-cavity exceeds the coupling coefficient between cavities in the array, atoms cannot be effectively coupled with each other through the edge states. Here, we generalize to higher-order structures and explore the dynamics of three atoms interacting with the cavity array based on the kagome-type optically coupled-cavity array with topologically protected corner states. Three atoms are theoretically coupled in three corner cavities, and various quantum behaviors can be displayed in different parameters. It is shown that three atoms mediated by the corner state can be coherently coupled with each other, without the constraint of the coupling coefficient, and can induce entanglement, which shows that the high-order topological optical structure has more advantages than the conventional topological optical structure in coherent coupling among qubits. In addition, we also studied atoms mediated by edge states. The results show that the atoms mediated by edge states can be coherently coupled only in the weak coupling regime, and the entanglement effect induced by the edge states is not as good as that of the corner state. It indicates that the corner state is more useful than the edge state in the second-order optical topological structure. Our results can offer references for applying optical topological structure in quantum computing and quantum communication.

Multipartite-entanglement generation in coupled microcavity arrays

We consider photonic arrays made from quantum emitters in optically coupled microcavities as a platform for entanglement generation. These offer a large degree of tunability with the possibility of site-selective optical excitation. Coherent pumping is considered to drive transitions between vacuum and entangled target states both in a time-dependent manner, and in a quantum bath engineering approach to create entanglement in the steady-state. We demonstrate a numerical scheme that allows to generalize the determination of excitation parameters to larger array sizes and different classes of entangled states. This study is a step towards using coupled cavity arrays as a hardware platform in novel quantum-photonic applications in quantum computing and quantum machine learning.

Phase transition and dynamics of qubits in coupled-cavity arrays with nonlinear topological photonics

The topological properties of a coupled-cavity array corresponding to a Su–Schrieffer–Heeger (SSH) model have been investigated through the evolution of a edge cavity, with the Kerr-like nonlinearities added to the inter-cavity coupling strengths. In the topological phase, the state distribution is more localized at the first cavity with the nonlinearities enhanced. The phase transition occurs with the enhancement of nonlinearities after the system evolving for long time when the SSH model is initially at the phase-transition point or in the trivial phase. The entanglement dynamics of two atoms placed in the two edge cavities is explored, and it is found the coupled-cavity array with nonlinearities is more robust against the disturbance of the frequency of each cavity. Moreover, the dynamics and phase transition of a 2-dimensional kagome lattice with the Kerr-like nonlinearities is also discussed through the probability amplitude of the first site after evolving for long time.

Chiral coupling between a ferromagnetic magnon and a superconducting qubit

Chiral coupling at the single-quantum level promises to be a remarkable potential for quantum information processing. Here we propose to achieve a chiral interaction between a magnon mode in a ferromagnetic sphere and a superconducting qubit mediated by a one-dimensional coupled-cavity array. When the qubit is coupled to two lattice sites of the array and each one is encoded with a tunable phase, we can acquire a directional qubit-magnon interaction via the quantum interference effect. This work opens up a new route to construct chiral devices, which are expected to become a building block in quantum magnonic networks.

Simulating topological phases with atom arrays in an optical waveguide

In this paper, we employ the atomic arrays in one-dimensional optical waveguides to simulate topological phases, where the waveguide is modeled as a one-dimensional infinitely long coupled cavity array. Under the Markov approximation, the coherent and dissipative coupling between atoms is established by eliminating waveguide modes. When the detuning between atoms and cavity fields lies in the band gap, the dynamics of the system is completely dominated by the coherent interaction. Under this condition, we designed three atomic arrays with different geometries and show that the topologically trivial and non-trivial phases of atomic arrays can be simulated. Furthermore, by introducing periodic atomic driving, the topological phase transition can be induced by adjusting the driving parameters. Finally, we investigate the effect of next-nearest neighbor interactions on topological state transfer and find that the next-nearest neighbor interactions break the degenerated bandgap state and establish a topological state transfer channel.

A review on quantum information processing in cavities

The processing of information and computation is undergoing a paradigmatic shift since the realization of the enormous potential of quantum features to perform these tasks. Coupled cavity array is one of the well-studied systems to carry out these tasks. It is a versatile platform for quantum networks for distributed information processing and communication. Cavities have the salient feature of retaining photons for longer durations, thereby enabling them to travel coherently through the array without losing them in dissipation. Many quantum information protocols have been implemented in arrays of coupled cavities. These advancements promise the suitability of cavity arrays for large-scale quantum communications and computations. This article reviews a few theoretical proposals and experimental realizations of quantum information tasks in cavities.

Nonperturbative waveguide quantum electrodynamics

Understanding physical properties of quantum emitters strongly interacting with quantized electromagnetic modes is one of the primary goals in the emergent field of waveguide quantum electrodynamics (QED). When the light-matter coupling strength is comparable to or even exceeds energies of elementary excitations, conventional approaches based on perturbative treatment of light-matter interactions, two-level description of matter excitations, and photon-number truncation are no longer sufficient. Here we study in and out of equilibrium properties of waveguide QED in such nonperturbative regimes on the basis of a comprehensive and rigorous theoretical approach using an asymptotic decoupling unitary transformation. We uncover several surprising features ranging from symmetry-protected many-body bound states in the continuum to strong renormalization of the effective mass and potential; the latter may explain recent experiments demonstrating cavity-induced changes in chemical reactivity as well as enhancements of ferromagnetism or superconductivity. To illustrate our general results with concrete examples, we use our formalism to study a model of coupled cavity arrays, which is relevant to experiments in superconducting qubits interacting with microwave resonators or atoms coupled to photonic crystals. We examine the relation between our results and delocalization-localization transition in the spin-boson model; notably, we point out that a reentrant transition can occur in the regimes where the coupling strength becomes the dominant energy scale. We also discuss applications of our results to other problems in different fields, including quantum optics, condensed matter physics, and quantum chemistry.

Effect of emitters on quantum state transfer in coupled cavity arrays

Over the last decade, conditions for perfect state transfer in quantum spin chains have been discovered and their experimental realizations addressed, as have their extensions to more complex geometries of coupled cavity-emitter arrays. In this paper we further consider such studies and situations in which quantum state transfer can occur with high fidelity, even when the cavity-cavity coupling rates and cavity-emitter interaction rates are comparable. This is accomplished through the development and use of a Monte Carlo approach to the inverse eigenvalue problem, which allows the determination of coupling rates which optimize quantum state transfer fidelity and subsequent time evolution of the polariton wave function through exact diagonalization of the resulting Jaynes-Cummings-Hubbard Hamiltonian. The effect of inhomogeneous emitter locations is also evaluated. Our key results include the demonstration that our methodology can be used successfully to establish Hamiltonian parameters for high-fidelity state transfer in more general lattice geometries and excitation number sectors, and also a determination of the effects of fluctuations in those parameters about their optimal values.

A Microelectronic Terahertz Source Using Multiple Field Emitter Cathodes With an Array of Coupled Cavities

Compact, high-power, and broad-spectral coverage terahertz sources have application prospects in diverse scientific and technological fields, which attract great interest from researchers. The recently developed microelectronic device, a so- called terahertz laser diode (TLD), affords a promising candidate to develop desirable terahertz sources. However, the performances and the accessibility of TLD have unavoidable restrictions in the practices. In this article, we propose an enhanced TLD, which uses multiple field-emitter cathodes with an array of coupled cavities. The power and efficiency can be several times higher than that in previous TLDs. The required electric field intensity and the emission current density from the field-emitter cathode can be significantly reduced, which enables established field-emitting materials to be applicable and decreases the manufacturing difficulty as well. In addition, the fields in different cavities can be coupled, forming a series of unified oscillation modes, which can work as operation modes with various output frequencies. This improved TLD is attractive for developing compact, high-power, and broad-spectrum coverage terahertz sources for practices.

Photonic rogue waves in a strongly dispersive coupled-cavity array involving self-attractive Kerr nonlinearity

Based on the combined Dicke, Bose-Hubbard, and Lipkin-Meshkov-Glick Hamiltonian, we investigate the formation of photonic rogue waves, including their Akhmediev and Kuznetsov-Ma cousins, in the strongly dispersive regime of a generalized atom-cavity array configuration. By means of the multiple-scale approach and mean-field approximation, we unveil that, due to the interplay between the photon hopping-induced tunneling effect and the self-attractive nonlinearity, the photons can redistribute in the whole array, which in turn leads to the redistribution (creation or annihilation) of excited atoms in each cavity and, consequently, the occurrence of Peregrine soliton states in both photonic and atomic fields. This interplay also yields an interesting intensity-clamping effect that the sum of the peak intensities of both rogue waves will be constant, although this quantity varies from site to site. We numerically confirm the analytical predictions, showing that the Peregrine rogue waves generated are stable against perturbations, despite the onset of modulation instability.

Quantum Switchboard with Coupled-Cavity Array

The ability to control the flow of quantum information is deterministically useful for scaling up quantum computation. In this paper, we demonstrate a controllable quantum switchboard which directs the teleportation protocol to one of two targets, fully dependent on the sender’s choice. Importantly, the quantum switchboard also acts as a optimal quantum cloning machine, which allows the receivers to recover the unknown quantum state with a maximal fidelity of . This protects the system from the complete loss of quantum information in the event that the teleportation protocol fails. We also provide an experimentally feasible physical implementation of the proposal using a coupled-cavity array. The proposed switchboard can be utilized for the efficient routing of quantum information in a large quantum network.

On the dissipative dynamics of entangled states in coupled-cavity quantum electrodynamics arrays

We examine the dissipative dynamics of N00N states with an arbitrary photon number N in two architectures of fiber-coupled optical ring resonators (RRs) interacting with two-level quantum emitters (QEs). One architecture consists of a two-way cascaded array of emitter–cavity systems, while in the other architecture, we consider two fiber-coupled RRs, each coupled to multiple dipole–dipole interacting (DDI) QEs. Our focus in this paper is to study how an initially prepared multiple excitation atomic N00N state transfers to the RRs and then how rapidly it decays in these open cavity quantum electrodynamics setups while varying the emitter–cavity coupling strengths, emitter–cavity detuning, and backscattering from cavity modes. We present a general theoretical formalism valid for any arbitrary numbers of QEs, RRs, and N numbers in the N00N state for both schemes. As examples, we discuss the cases of single- and two-excitation N00N states and report the comparison of our findings in both schemes. As one of the main results, we conclude that the array scheme tends to store N00N for longer times, while the DDI scheme supports higher fidelity values. The results of this study may find applications in designing new multiparty entanglement-based protocols in quantum metrology and quantum lithography.