Serwis Infona wykorzystuje pliki cookies (ciasteczka). Są to wartości tekstowe, zapamiętywane przez przeglądarkę na urządzeniu użytkownika. Nasz serwis ma dostęp do tych wartości oraz wykorzystuje je do zapamiętania danych dotyczących użytkownika, takich jak np. ustawienia (typu widok ekranu, wybór języka interfejsu), zapamiętanie zalogowania. Korzystanie z serwisu Infona oznacza zgodę na zapis informacji i ich wykorzystanie dla celów korzytania z serwisu. Więcej informacji można znaleźć w Polityce prywatności oraz Regulaminie serwisu. Zamknięcie tego okienka potwierdza zapoznanie się z informacją o plikach cookies, akceptację polityki prywatności i regulaminu oraz sposobu wykorzystywania plików cookies w serwisie. Możesz zmienić ustawienia obsługi cookies w swojej przeglądarce.
We report an experimental study of a new technique for spin cooling an ensemble of ultracold atoms via quantum non-demolition (QND) measurement and incoherent feedback. We have demonstrated 12db spin noise reduction. This technique has direct application in generating highly entangled macroscopic singlet states.
Angiosarcoma is a rare malignant neoplasm of mesenchymal origin. It is characterised by endothelial differentiation. Lesions are most commonly seen in the head and neck region, especially on the skin of the scalp in elderly men. Oral and intraosseous lesions are comparatively rare. We report an exceedingly rare case of primary intraosseous angiosarcoma in a 79‐year‐old male arising in the mandibular...
We present the quadrature and polarization squeezing generated by a sub-threshold optical parametric oscillator (OPO) resonant to rubidium D1 line and pumped by a frequency-doubled diode laser. We demonstrate here a technique to eliminate the effects of laser phase noise on quadrature squeezing. The technique uses cavity stabilization of the laser frequency, in combination with a carefully chosen...
The paper studies the second kind of entanglement distribution scheme. Entangled photon pairs are generated using the type-II spontaneous parametric down-conversion process (SPDC) in a PPKTP crystal. The source is tunable to both D-P transitions at 850 and 854 nm in 40Ca+ ions. The photon pairs are split by a polarizing beam splitter and one photon mode is coupled into a filtering line, consisting...
There has been increasing interest in the generation of such photon pairs using a spontaneous parametric down-conversion (SPDC) source inside an optical cavity to enhance the down-conversion into modes resonant to the cavity, each of the modes having a MHz spectrum. These optical parametric oscillators (OPO) operated far below threshold also provide a well defined spatial mode. Our setup consists...
Atom-photon interaction promises to be a fundamental resource for applications like quantum computations. For an efficient interaction between light and atoms, the bandwidth of the light should match the natural linewidth of the atom transition to address, 6 MHz in the case of the Di line of rubidium. Cavity-enhanced down-conversion (CEDC) produces bright narrow-band quantum light with suitable linewidth...
Atomic ensembles have gained a lot of interest in the last decade for their prospective use as quantum memories, in precision measurements and other applications in quantum information processing. The atomic part of the interface presented here is an all-optically trapped atomic ensemble of 87Rb at a temperature of 25 muK. The ensemble consists of 106 atoms and has an elongated shape with an aspect...
This work considers an atom-light interface consisting of pulses of polarized light that interacts with an ensemble of 106 cold 87Rb in dipole trap. Measurements of polarization changes in the light is used in probing the atomic state. In such polarization-based atom-light interface, a Hamiltonian nonlinear in the Stokes operators can be produced through optical nonlinearities. This work investigates...
We present a tunable, frequency-stabilized, narrow-bandwidth source of frequency-degenerate, entangled photon pairs, which can address the two D-P transitions in 40Ca+ ions. We also demonstrate single ion-single photon interaction by the detection of quantum jumps.
We use narrow-band quantum light sources, tuned to the rubidium D1 resonance, to produce polarization-squeezed and polarization-NooN states for Heisenberg-limited measurements on atoms. By paramagnetic Faraday rotation these states measure the atomic spin polarization.
Highly sensitive Faraday rotation measurements are performed on an ensemble of 87Rb. The deduced interaction strength is discussed in the context of spin squeezing. We present a method for spin state tomography based on Faraday rotation measurements.
We describe an ultra-bright source of narrow-band pairs of indistinguishable photons based on cavity-enhanced down-conversion. This source is suitable for experiments on light-matter interactions at the single-photon level.
Effective interactions between a cold atomic ensemble and probe light can take the ldquoQND,rdquo ldquobeamsplitter,rdquo and ldquotwo-mode squeezingrdquo forms, useful for quantum cloning and memory. We describe experiments with dipole-trapped 87Rb using these interactions.
In this paper, we present a technically improved source of such rubidium resonant squeezed light. It uses a new pumping laser system and a technologically advanced locking scheme. To produce squeezed light, we use the proven technique of downconversion within a subthreshold OPO but with one distinct difference: our OPO is not pumped by a Ti:Sapphire laser, but by a diode laser system. This system...
Spin squeezed states can be used to improve the performance of atomic clocks and magnetometers. Recently, atom-light interaction of a similar type has also been used to demonstrate quantum memory and quantum teleportation between light and matter. Furthermore, this interaction facilitates studies in the field of controlled quantum dynamics.
Light interacting with atomic ensembles allows the possibility of strong, and thus deterministic, quantum interface processes. Recently demonstrated processes of interest for quantum networking include quantum memory for light and teleportation of a quantum state from light to matter. Many important results have been accomplished with room temperature ensembles, which has thus far limited the experiments...
This article proposes a model that provides important insights into the effect of inhomogeneities in atom-light interactions. This model is able to handle all different kinds of inhomogeneities. Moreover, it simulates the influence of imperfect temporal detector resolution.
We present the design and set-up of a narrow-bandwidth source of entangled photon pairs, which will allow us to address the transitions D3/2-P3/2 and D5/2-P3/2 in 40Ca+ ions at 850 and 854 nm wavelength, respectively. The source has been designed to emit photons with a high spectral power density into the absorption window of the Calcium ions, which has a bandwidth of ~20 MHz. The design has been...
We present recent experiments on production of entangled states using linear optical elements and post-selection. Using quantum information techniques including state and process tomography, we characterize strategies for producing Bell states and multi-photon entangled states
Recent results demonstrating superluminal group velocities and tachyonic dispersion relations reopen the question of superluminal signals and causal loop paradoxes. The sense in which superluminal signals are permitted is explained in terms of pulse reshaping, and the self-consistent behavior which prevents causal loop paradoxes is illustrated by an explicit example.
Podaj zakres dat dla filtrowania wyświetlonych wyników. Możesz podać datę początkową, końcową lub obie daty. Daty możesz wpisać ręcznie lub wybrać za pomocą kalendarza.