Search results for "cavity quantum electrodynamics"
showing 10 items of 65 documents
Génération et interfaçage de lumière à photon unique et contrôle de la dynamique atomique ultra-rapide pour l’information quantique
2010
We develop a robust and realistic mechanism for the generation of indistinguishable single-photon (SP) pulses with identical frequency and polarization. They are produced on demand from a coupled double-Raman atom-cavity system driven by a sequence of laser pump pulses. This scheme features a high efficiency, the ability to produce a sequence of narrow-band SP pulses with a delay determined only by the pump repetition rate, and simplicity of the system free from complications such as repumping process and environmental dephasing. We propose and analyze a simple scheme of parametric frequency conversion for optical quantum information in cold atomic ensembles. Its remarkable properties are m…
Effects of an environment on a cavity-quantum-electrodynamics system controlled by bichromatic adiabatic passage
2012
International audience; We present a theoretical investigation of a cavity-QED system controlled by bichromatic adiabatic passage in a dissipative environment. We analyze the production of a controlled Fock state in the cavity by a traveling atom simultaneously coupled by a laser field, and the leakage of the corresponding photons from the cavity.
Quantum Computing with Trapped Charged Particles
2009
The concept of quantum computing has no clear cut origin. It emerged from combinations of information theory and quantum mechanical concepts. A decisive step was taken by Feynman [414, 415] who considered the possibility of universal simulation, a quantum system which could simulate the physical behavior of any other. Feynman gave arguments which suggested that quantum evolution could be used to compute certain problems more efficiently than any classical computer. His device may be considered as not sufficiently specified to be called a computer. The next important step was taken in 1985 by Deutsch [310]. His proposal is generally considered to represent the first blueprint for a quantum c…
Quantum-state manipulation via quantum nondemolition measurements in a two-dimensional trapped ion
2001
The quantum nondemolition measurement is applied to a two-dimensional (2D) trapped-ion model in which two laser beams drive the corresponding vibrational motions and are carrier resonant with the two-level system of the ion. The information about the ionic vibrational energy can be detected by the occupation probability of the internal electronic level. The substantial difference of the 2D model from the one-dimensional one is that two orthogonal beams have a fixed phase shift instead of statistical independence. As a result, the atomic Rabi oscillation is involved in the coherent superposition of two sub-Rabi oscillations induced by the corresponding driving beams. This means that, in the …
Quantum Nondemolition Measurement and Quantum State Manipulation in Two Dimensional Trapped Ion
2001
An extension of QNDmeasuremen t of the vibrational energy of the trapped ion from one dimensional case to the bidimensional one is presented. Our approach exploits the fixed phase difference existing between the two orthogonal and appropriately configured classical laser beams determining the vibronic coupling. We in fact show that this phase difference may play the role of an adjustable external parameter which allows to optimize the measurement scheme itself in terms of both precision and sensitivity. Our proposal provides a cooling method for the trapped ion from the vibrational thermal state. Due to the coherent superposition of two sub Rabi oscillations, the Rabi frequency degeneration…
Quantum noise properties of cavity solitons
2006
General method for studying quantum fluctuations of dissipative structures formed in nonlinear optical cavities is presented. Application to cavity soliton supported by degenerate optical parametric oscillator is presented. Squeezing and intensity fluctuations spectra are discussed.
Far-infrared laser on quantum dots created by electric-field focusing
2003
The new proposal of a far-infrared laser employing intraband transitions in the system of quantum dots is briefly described. The conditions for inversion of population for electrons in the quantum dot matrix created by an electric-field focusing in narrow GaAs/AlGaAs quantum well are discussed. The laser is planned to be pumped by periodically repeated rapid creation and destruction of the quantum dot matrix allowing for repeated filling of the dot levels with electrons from a quantum well. Some major results of the analysis of the kinetics of the electron-photon system are presented.
Photon Production from the Vacuum Close to the Superradiant Transition: Linking the Dynamical Casimir Effect to the Kibble-Zurek Mechanism
2012
The dynamical Casimir effect (DCE) predicts the generation of photons from the vacuum due to the parametric amplification of the quantum fluctuations of an electromagnetic field. The verification of such an effect is still elusive in optical systems due to the very demanding requirements of its experimental implementation. We show that an ensemble of two-level atoms collectively coupled to the electromagnetic field of a cavity, driven at low frequencies and close to a quantum phase transition, stimulates the production of photons from the vacuum. This paves the way to an effective simulation of the DCE through a mechanism that has recently found experimental demonstration. The spectral prop…
Quantum control and long-range quantum correlations in dynamical Casimir arrays
2015
The recent observation of the dynamical Casimir effect in a modulated superconducting waveguide, coronating thirty years of world-wide research, empowered the quantum technology community with a powerful tool to create entangled photons on-chip. In this work we show how, going beyond the single waveguide paradigm using a scalable array, it is possible to create multipartite nonclassical states, with the possibility to control the long-range quantum correlations of the emitted photons. In particular, our finite-temperature theory shows how maximally entangled $NOON$ states can be engineered in a realistic setup. The results here presented open the way to new kinds of quantum fluids of light,…
Is massless quantum electrodynamics a free-field theory?
1976
It is shown that if the photon wave-function renormalization constant is finite, then in the limit of zero fermion mass, quantum electrodynamics is a free- field theory.