We experimentally demonstrate a ring geometry all-fiber cavity system for cavity quantum electrodynamics with an ensemble of cold atoms. The fiber cavity contains a nanofiber section which mediates atom-light interactions through an evanescent field. We observe well-resolved, vacuum Rabi splitting of the cavity transmission spectrum in the weak driving limit due to a collective enhancement of the coupling rate by the ensemble of atoms within the evanescent field, and we present a simple theoretical model to describe this. In addition, we demonstrate a method to control and stabilize the resonant frequency of the cavity by utilizing the thermal properties of the nanofiber.In the context of scalable quantum computing and quantum communication, one can envision a network of quantum systems, or nodes, linked together through appropriate quantum channels to form a quantum network [1][2][3]. These networks have a wide variety of applications, from quantum computation [4] to simulating many-body quantum systems [5]. The use of photons for quantum communication is well established [6], and hence quantum nodes require an efficient light-matter interface. Cavity quantum electrodynamics (QED) has been at the forefront of implementing strong, coherent atom-light interactions [7][8][9], and the ability of cavity QED systems to control and manipulate the quantum states of light and matter make them perfect candidates for quantum nodes [10]. For example, free-space Fabry-Pérot cavities have been used to implement an elementary quantum network consisting of two nodes [11].To overcome the complexity and poor scalability of free-space cavities, fiber-based alternatives are required in order to realize a large scale quantum network. When implementing an all-fiber quantum node, a useful component for achieving strong coupling between fiber guided light and atoms is an optical nanofiber. Such a nanofiber offers tight transversal-mode confinement and large evanescent fields, and therefore allows for efficient atom-light coupling [12,13], as well as nonlinear atomlight interactions at very low optical powers [14]. Recently, these nanofibers have been utilized to demonstrate a memory for light [15,16].The atom-light interaction can be further enhanced by the use of a fiber cavity. One such configuration utilizes a nanofiber section sandwiched between two fiberBragg gratings to form an all-fiber Fabry-Pérot cavity [17]. Strong optical coupling with a single cesium atom has been demonstrated in this system, with a moderate cavity finesse (F < 40), due to high quality trapping of the atom near to the nanofiber surface [18].An alternative ring geometry has been recently studied using a low finesse fiber cavity with a hot atomic vapor of rubidium, where it was seen that the cavity transmission varied as the probe frequency was scanned across the * sam.ruddell@auckland.ac.nz Doppler-broadened atomic resonance [19]. Furthermore, in a recent proposal, a ring cavity geometry has been suggested as a potential platform for studying multimode stro...
We report on an experimental realization of unidirectional transporting island structures in an otherwise chaotic phase space of the δ-kicked rotor system. Using a Bose-Einstein condensate as a source of ultracold atoms, we employ asymmetric phase modulation in the kicks, with the narrow momentum distribution of the atoms allowing us to address individual island structures. We observe quantum ratchet behavior in this system, with clear directed momentum current in the absence of a directional force, which we characterize and connect to -classical theory.
We experimentally investigate the effects of phase noise on the resonant and non-resonant dynamics of the atom-optics kicked rotor. Employing sinusoidal phase modulation at various frequencies, resonances are found corresponding to periodic phase shifts, resulting in the effective transformation of quantum antiresonances into resonances and vice-versa. The stability of the resonance is analysed, with the aid of experiments, ϵ-classical theory and numerical simulations, and is found to be surprisingly robust against phase noise. Finally we look into the effects of phase noise on dynamical localization and discuss the destruction of the localization in terms of decoherence.
We demonstrate the fabrication of ultra-low-loss, all-fiber Fabry–Perot cavities that contain a nanofiber section, optimized for cavity quantum electrodynamics. By continuously monitoring the finesse and fiber radius during the fabrication of a nanofiber between two fiber Bragg gratings, we were able to precisely evaluate taper transmission as a function of radius. The resulting cavities have an internal round-trip loss of only 0.31% at a nanofiber waist radius of 207 nm, with a total finesse of 1380, and a maximum expected internal cooperativity of ∼ 1050 for a cesium atom on the nanofiber surface. Our ability to fabricate such high-finesse nanofiber cavities may open the door for the realization of high-fidelity scalable quantum networks.
We review the theoretical model and experimental realization of the atom optics δ−kicked rotor (AOKR), a paradigm of classical and quantum chaos. We have performed a number of experiments with an all-optical Bose-Einstein condensate (BEC) in a periodic standing wave potential in an AOKR system. We discuss results of the investigation of the phenomena of quantum resonances in the AOKR. An interesting feature of the momentum distribution of the atoms obtained as a result of short pulses of light, is the variance of the momentum distribution or the kinetic energy p 2 /2m in units of the recoil energy E rec =hω rec . The energy of the system is examined as a function of pulse period for a range of kicks that allow the observation of quantum resonances.In particular we study the behavior of these resonances for a large number of kicks. Higher order quantum resonant effects corresponding to the fractional Talbot time of (1/4)T T and (1/5)T T for five and ten kicks have been observed. Moreover, we describe the effect of the initial momentum of the atoms on quantum resonances in the AOKR.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.