We investigate the time evolution of the photon-detection probability at various output ports of an all-fiber coupled cavity-quantum-electrodynamics (cavity-QED) system. The setup consists of two atoms trapped separately in the field of two nanofiber cavities that are connected by a standard optical fiber. We find that the normal-mode picture captures well the main features of the dynamics. However, a more accurate description based on the diagonalization of a non-Hermitian Hamiltonian reveals the origin of small yet significant features in the spontaneous emission spectra.
We investigate the time evolution of the photon-detection probability at various output ports of an all-fiber coupled cavity-quantum-electrodynamics (cavity-QED) system. The setup consists of two atoms trapped separately in the field of two nanofiber cavities that are connected by a standard optical fiber. We find that the normal-mode picture captures well the main features of the dynamics. However, a more accurate description based on the diagonalization of a non-Hermitian Hamiltonian reveals the origin of small yet significant features in the spontaneous emission spectra.
In a cavity quantum electrodynamics (QED) system, where atoms coherently interact with photons in a cavity, the eigenstates of the system are the superposition states of atoms and cavity photons, the so-called dressed states of atoms. When two cavities are connected by an optical fiber with negligible loss, the coherent coupling between the cavities gives rise to photonic normal modes. One of these normal modes is the fiber-dark mode, in which photons are delocalized in the two distant cavities. Here we demonstrate the setting of coupled-cavities QED, where two nanofiber cavity-QED systems are coherently connected by a meter-long low-loss channel in an all-fiber fashion. Specifically, we observe dressed states of distant atoms with delocalized photons of the fiber-dark normal mode. Our system will provide a platform for the study of delocalized atomic and photonic states, photonic many-body physics, and distributed quantum computation.
Abstract In a cavity quantum electrodynamics (QED) system, where atoms coherently interact with photons in a cavity, the eigenstates of the system are the superposition states of atoms and cavity photons, the so-called dressed states of atoms. When two cavities are connected by an optical fiber with negligible loss, the coherent coupling between the cavities gives rise to photonic normal modes. One of these normal modes is the fiber-dark mode, in which photons are delocalized in the two distant cavities. Here we demonstrate the setting of coupled-cavities QED, where two nanofiber cavity-QED systems are coherently connected by a meter-long low-loss channel in an all-fiber fashion. Specifically, we observe dressed states of distant atoms with delocalized photons of the fiber-dark normal mode. Our system will provide a platform for the study of delocalized atomic and photonic states, photonic many-body physics, and distributed quantum computation.
We consider a system consisting of a Λ-type atom and a V-type atom which are individually trapped in two spatially separated cavities that are connected by an optical fiber.The evolutions of the excitions of atom 1,atom 2,cavity A,cavity B and fiber mode are given.We discuss the influence of cavity-fiber coupling coefficient on the excitions.The results obtained by the numerical method show that the excitions of cavity A and cavity B decrease with increase of the cavity-fiber coupling coefficient.On the other hand,the excition of fiber mode shows a nonlinear variation with increase of the cavity-fiber coupling coefficient.
Optical nanofibers provide a versatile platform for exploring strong light-matter interactions at the single-quantum level, a central goal of quantum optics. Their subwavelength diameter supports tightly confined guided modes with strong evanescent fields, enabling efficient coupling between photons and nearby atoms. By incorporating fiber Bragg gratings, nanofibers can form fully fiber-integrated high-finesse cavities, combining strong atom-photon coupling with efficient and low-loss optical input-output interfacing in the setting of cavity quantum electrodynamics (QED). In parallel, nanofiber systems naturally realize waveguide QED, where atoms interact strongly with propagating photons in a one-dimensional geometry. In this review, we introduce the underlying physical principles, summarize key experimental techniques and representative phenomena, and discuss prospects for applications in quantum information processing, quantum networks, and related quantum technologies.
Cavity quantum electrodynamics (QED) allows the study of light-matter in-teractions at the most basic level, through precise identification of the coherent and incoherent (dissipative) parts of the system evolution. We present measurements of light from a cavity QED system consisting of a high-finesse optical resonator coupled to a beam of cold Rb atoms. The novelty of the design lies in the interplay of two degenerate and orthogonal polarization modes. One mode (driven) behaves as the canonical cavity mode of the Jaynes-Cummings Hamiltonian, coherently exciting the atoms with a modest coupling strength; the other mode (undriven) collects a small fraction of spontaneously emitted light and provides a probe of the dissipative processes. We first demonstrate the ability to detect individual atoms passing through the cavity modes in real time by coincidence detection of photons from the un-driven mode. Calculation of statistics and correlation functions from the complete photon detection record allows the determination of detection probabilities and the reconstruction of atomic trajectories. We next present evidence of quantum coher-ence that is created, modified, and measured in the excitation-spontaneous emission cycle. The coherence appears as a long-lived quantum beat at the ground-state Larmor frequency, visible in the intensity autocorrelation function of the undriven mode. Quantum jumps of the atomic state, occurring in between the detections of photons from the cavity, result in substantial changes in the frequency and spectral width of the beats. We present the results of a full quantum Monte Carlo calculation in order to quantitatively explain the measurements.
We investigate a two-way cascaded cavity QED system consisting of microtoroidal resonators coupled through an optical fiber. Each microtoroidal cavity supports two counterpropagating whispering-gallery modes coupled to single atoms through their evanescent fields. We focus on a pair of atom-microtoroid systems and compute the spectrum of spontaneous emission into the fiber with one atom initially excited. Explicit results are presented for strong-coupling and bad-cavity regimes, where the latter allows the effective atom-atom interaction to be controlled through the atom-cavity coupling and detuning: the atoms exhibit either collective spontaneous emission with no dipole-dipole interaction or a (coherent) dipole-dipole interaction and independent (single-atom) emission. This capacity for switching the character of the interaction is a feature of bidirectional coupling and connects our two-way cascaded system to work on one-dimensional waveguides. Building upon our bad-cavity results, we generalize to many atom-microtoroid systems coupled through an optical fiber.