We investigate the enhanced generation of the optical second-order sideband (OSS) via magnon Kerr nonlinearity from a cavity magnonical hybrid system consisting of a single small yttrium iron garnet (YIG) crystal sphere and a three-dimensional (3D) rectangular cavity driven with a weak probe and a strong control field. Beyond the linear approximation, we solve the nonlinear Heisenberg–Langevin equations for achieving the analytical solutions by employing the perturbation technique. Using the experimentally achievable parameter settings, we demonstrate that the OSS generation can be significantly enhanced via increasing the magnon Kerr nonlinearity even if the coupling between the cavity and magnon is weak. Interestingly, two-color OSS generation can be observed when the cavity-magnon coupling is in the strong-coupling regime, which results from the magnonical polaritons induced by the hybrid of cavity and magnon modes. The present results illustrate the potential to utilize magnon Kerr nonlinearity for enhancing optical higher-order sidebands and controlling optical frequency combs, as well as to guide the design of experimental implementation.
We investigate the enhanced generation of the optical second-order sideband (OSS) via magnon Kerr nonlinearity from a cavity magnonical hybrid system consisting of a single small yttrium iron garnet (YIG) crystal sphere and a three-dimensional (3D) rectangular cavity driven with a weak probe and a strong control field. Beyond the linear approximation, we solve the nonlinear Heisenberg–Langevin equations for achieving the analytical solutions by employing the perturbation technique. Using the experimentally achievable parameter settings, we demonstrate that the OSS generation can be significantly enhanced via increasing the magnon Kerr nonlinearity even if the coupling between the cavity and magnon is weak. Interestingly, two-color OSS generation can be observed when the cavity-magnon coupling is in the strong-coupling regime, which results from the magnonical polaritons induced by the hybrid of cavity and magnon modes. The present results illustrate the potential to utilize magnon Kerr nonlinearity for enhancing optical higher-order sidebands and controlling optical frequency combs, as well as to guide the design of experimental implementation.
We propose and analyze an effective scheme to enhance the optical higher-order sideband generation in a three-cavity array with local parity-time (PT) symmetry. In this three-cavity configuration, a single cavity containing a quantum dot (QD) is coupled to an assisted PT-symmetric combination of two cavities. Beyond the weak-excitation approximation, we derive the analytic formulas used to determine the nonlinear coefficient of the optical second-order sideband (OSS) by employing the perturbation technique. Using experimentally achievable parameters, we identify the conditions under which the assisted PT-symmetric double-cavity system allows us to modify the transmission of the probe field and improve the efficiency of OSS generation beyond what is achievable in a loss-only QD-cavity system. We examine the influence of the PT phase transition from unbroken- to broken-PT regimes on the OSS generation. It is found that the efficiency of optical second-order sideband generation can be significantly enhanced when the assisted double-cavity system is in PT-symmetric phase, extremely in the vicinity of the transition point. The present results illustrate the potential to utilize PT-symmetric physical systems for enhancing optical higher-order sidebands and controlling optical frequency combs, as well as to guide the design of experimental implementation.
We experimentally demonstrate magnon Kerr effect in a cavity quantum electrodynamics (QED) system, where magnons in a small yttrium iron garnet (YIG) sphere are strongly but dispersively coupled to the photons in a three-dimensional cavity. When the YIG sphere is pumped to generate considerable magnons, the Kerr effect yields a perceptible shift of the cavity central frequency and more appreciable shifts of the magnon modes. We derive an analytical relation between the magnon frequency shift and the drive power for the uniformly magnetized YIG sphere and find that it agrees very well with the experimental results of the Kittel mode. Our study paves the way to explore nonlinear effects in the cavity QED system with magnons.
We propose an alternative scheme to achieve the cross-correlations between magnon and photon in a hybrid nonlinear system including two microwave cavities and one yttrium iron garnet (YIG) sphere, where two cavities nonlinearly interact and meanwhile one of cavities couples to magnon representing the collective excitation in YIG sphere via magnetic dipole interaction. Based on dispersive couplings between two cavities and between one cavity and magnon with the larger detunings, the nonlinear interaction occurs between the other cavity and magnon, which plays a crucial role in generating quantum correlations. By analyzing the second-order correlation functions via numerical simulations and analytical calculations, the remarkable nonclassical correlations are existent in such a system, where the magnon blockade and photon antibunching could be obtainable on demand. The scheme we present is focused on the magnon-photon cross-correlations in the weak coupling regime and relaxes the requirements of experimental conditions, which may have potential applications in quantum information processing in the hybrid system.
Hybrid quantum systems have attracted much attention due to the fact that they combine the advantages of different physical subsystems. Cavity QED (cavity quantum electrodynamics) with magnons is a hybrid quantum systems that combines a YIG (Yttrium Iron Garnet) sphere and a 3D (three-dimensional) rectangular microwave cavity. Based on this hybrid photon-magnon system, we obtain an approximate analytic solution by the RWA (rotating wave approximation) with an ingenious transformation. After skillfully diagonalizing the Hamiltonian, we show that the Kerr-nonlinearity interactions could yield a negativity value of the Wigner function, periodic quadrature squeezing effects, antibunching property, and field nonclassicality in the magnon. Our work may stimulate the study of nonclassicality of photon-magnon coupling systems and its potential applications in quantum information processing.
In the past few years, the emerging photon-magnon dissipative coupling offers us an effective way to design and exploit losses to fulfill quantum tasks in hybrid cavity magnonics systems. In this paper, we theoretically investigate the dissipative-coupling-induced transparency (DCIT) and the enhancement of the high-order sidebands in a dissipative photon-magnon coupling system with Kerr nonlinearity. We find that the DCIT can be observed with both a weak and strong driving field. Due to the existence of the Kerr nonlinearity and introduction of the strong driving field of magnon, the sidebands can be enhanced highly by choosing the optimized parameters. In order to find the optimized parameters to enhance sidebands, we utilize the eigenvalues of the effective Hamiltonian to find the critical point of the stability region, near which sidebands can be enhanced in maximal degree.
Nonclassical states of quantized light are essential resources for quantum information science and emerging quantum technologies. In this work, we investigate the generation of such states in a dissipative hybrid system, namely a microcavity consisting of a ferromagnetic yttrium iron garnet (YIG) sphere coupled to a quantized microwave cavity mode, and particularly incorporating several nonlinear quantum optical elements including various Kerr media, optical parametric amplifier (OPA), and a magnonic parametric amplifier (MPA) which is introduced as the magnonic analog of the OPA. Decoherence effects arise from thermal photonic and magnonic reservoirs. Using the Heisenberg–Langevin formalism, we analyze the influence of Kerr nonlinearities, OPA, and MPA on several nonclassical signatures, including antibunching, entanglement, quadrature squeezing, and violation of the Cauchy–Schwarz inequality. Numerical results show that photon and magnon antibunching, as well as violation of the Cauchy–Schwarz inequality, can persist even in the presence of considerable dissipation, although these effects weaken as the thermal photon and magnon populations increase. In contrast, entanglement and quadrature squeezing remain remarkably robust against thermal noise. Furthermore, we demonstrate that the inclusion of OPA and MPA generally enhances all investigated nonclassical effects, whereas Kerr nonlinearities have negligible influence within the considered parameter regimes.