Demonstration of the spatial separation of the entangled quantum sidebands of an optical field

Quantum optics experiments on bright beams are based on the spectral analysis of field fluctuations and typically probe correlations between radio-frequency sideband modes. However, the extra degree of freedom represented by this dual-mode picture is generally ignored. We demonstrate the experimental operation of a device which can be used to separate the quantum sidebands of an optical field. We use this device to explicitly demonstrate the quantum entanglement between the sidebands of a squeezed beam.

Coherent-state linear optical quantum computing gates using simplified diagonal superposition resource states

In this paper we explore the possibility of fundamental tests for coherent-state optical quantum computing gates [ T. C. Ralph et al. Phys. Rev. A 68 042319 (2003)] using sophisticated but not unrealistic quantum states. The major resource required in these gates is a state diagonal to the basis states. We use the recent observation that a squeezed single-photon state [S(r)∣1⟩] approximates well an odd superposition of coherent states (∣α⟩−∣−α⟩) to address the diagonal resource problem. The approximation only holds for relatively small α, and hence these gates cannot be used in a scalable scheme. We explore the effects on fidelities and probabilities in teleportation and a rotated Hadamard gate.

Production of superpositions of coherent states in traveling optical fields with inefficient photon detection

We develop an all-optical scheme to generate superpositions of macroscopically distinguishable coherent states in traveling optical fields. It nondeterministically distills coherent-state superpositions (CSS's) with large amplitudes out of CSS's with small amplitudes using inefficient photon detection. The small CSS's required to produce CSS's with larger amplitudes are extremely well approximated by squeezed single photons. We discuss some remarkable features of this scheme: it effectively purifies mixed initial states emitted from inefficient single-photon sources and boosts negativity of Wigner functions of quantum states.

Time-evolution of highly localized positive-energy states of the free Dirac electron

Highly localized positive-energy states of the free Dirac electron are constructed and shown to evolve in a simple way under the action of Dirac's equation. When the initial uncertainty in position is small on the scale of the Compton wavelength, there is an associated uncertainty in the mean energy that is large compared with the rest mass of the electron. However, this does not lead to any breakdown of the one-particle description, associated with the possibility of pair-production, but rather leads to a rapid expansion of the probability density outwards from the point of localization, at speeds close to the speed of light.

Adaptive phase measurements for narrowband squeezed beams

We have previously [Phys. Rev. A 65, 043803 (2002)] analyzed adaptive measurements for estimating the continuously varying phase of a coherent beam, and a broadband squeezed beam. A real squeezed beam must have finite photon flux N and hence can be significantly squeezed only over a limited frequency range. In this paper we analyze adaptive phase measurements of this type for a realistic model of a squeezed beam. We show that, provided it is possible to suitably choose the parameters of the beam, a mean-square phase uncertainty scaling as (N/kappa)(-5/8) is possible, where kappa is the linewidth of the beam resulting from the fluctuating phase. This is an improvement over the (N/kappa)(-1/2) scaling found previously for coherent beams. In the experimentally realistic case where there is a limit on the maximum squeezing possible, the variance will be reduced below that for coherent beams, though the scaling is unchanged.

Signatures for generalized macroscopic superpositions

We develop criteria sufficient to enable detection of macroscopic coherence where there are not just two macroscopically distinct outcomes for a pointer measurement, but rather a spread of outcomes over a macroscopic range. The criteria provide a means to distinguish a macroscopic quantum description from a microscopic one based on mixtures of microscopic superpositions of pointer-measurement eigenstates. The criteria are applied to Gaussian-squeezed and spin-entangled states.

Mixed-state entanglement in the light of pure-state entanglement constrained by superselection rules

We show that the classification of bi-partite pure entangled states when local quantum operations are restricted, e.g., constrained by local superselection rules, yields a structure that is analogous in many respects to that of mixed-state entanglement, including such exotic phenomena as bound entanglement and activation. This analogy aids in resolving several conceptual puzzles in the study of entanglement under restricted operations. Specifically, we demonstrate that several types of quantum optical states that possess confusing entanglement properties are analogous to bound entangled states. Also, the classification of pure-state entanglement under restricted operations can be much simpler than for mixed state entanglement. For instance, in the case of local Abelian superselection rules all questions concerning distillability can be resolved.

Determination of the Pu autoionizing level angular momenta by a multistep excitation with linearly polarized laser light

The modified polarization spectroscopy method was applied for determination of angular momenta of autoionizing states of Pu in multistep resonance ionization processes. In comparison with the known one, our method does not require circular polarization at all, only linear polarizations are needed. This simplicity was reached using a three-dimensional excitation geometry. Angular momenta of nine new autoionizing ²⁴²Pu states were determined. The method suggested could be applied for efficiency improvement in multistep RIMS applications as well as for the odd-even isotope separation for elements with a J = 0 ground state (Pu, Yb, Sm etc.).

Tíz év az Európai Unióban - az új tagországok agrárteljesítményei = A decade in the EU: the agricultural performances of the new member-states

Több mint tíz év telt el az Európai Unió 2004. évi kibővülése óta. A tízéves évforduló jó lehetőséget kínált a mérlegkészítésre, annak vizsgálatára, hogy a legfrissebb elérhető adatok tükrében milyen fejlődési pályát tudhatnak maguk mögött az új tagországok mezőgazdasági szektorai. Írásunk célja a tíz kelet- európai EU-tagállam agrárteljesítményének értékelése, illetve ez alapján a csatlakozás nyerteseinek, illetve veszteseinek azonosítása. A rendelkezésre álló adatokat a többdimenziós faktoranalízis módszerével feldolgozva arra az eredményre jutottunk, hogy Lengyelország, Észtország és Litvánia hármasa tekinthető az agrárcsatlakozás abszolút nyertesének, míg a többi új tagállam nem volt képes teljes mértékben kihasználni a csatlakozás adta lehetőségeket. Az eredményekből az is látható, hogy a magas hozzáadott értékű termékekre való szakosodás jó stratégiának bizonyult, mert gyorsabb fejlődést biztosított, mint a mezőgazdasági alaptermékekre való koncentrálás. ____ The period of over ten years since the 2004 round of EU accessions provides a good opportunity to assess and take stock of agricultural developments in the new member- States, in light of the latest available data. The paper sets out to assess their agricultural performances and to identify the winners and losers by accession in this regard. Ranking individual country performances using Parallel Factor Analysis (PARAFAC) suggests that Poland, Estonia and Lithuania can be considered as winners, whereas the other countries failed to use the potentials of membership to the full. The results also suggest that focusing on agri-food products with a high added value proved a good development strategy for the sector. Countries that concentrated on producing agri-food raw materials lagged behind.

Spectroscopy of Electroproduced Light to Medium Mass Lambda Hypernuclei

The E01-011 experiment at Jefferson Laboratory (JLab) studied light-to-medium mass Λ hypernuclei via the AZ + e → [special characters omitted] + e' + K+ electroproduction reaction. Precise measurement of hypernuclear ground state masses and excitation energies provides information about the nature of hyperon-nucleon interactions. Until recently, hypernuclei were studied at accelerator facilities with intense π+ and K- meson beams. The poor quality of these beams limited the resolution of the hypernuclear excitation energy spectra to about 1.5 MeV (FWHM). This resolution is not sufficient for resolving the rich structure observed in the excitation spectra. By using a high quality electron beam and employing a new high resolution spectrometer system, this study aims to improve the resolution to a few hundred keV with an absolute precision of about 100 keV for excitation energies. In this work the high-resolution excitation spectra of [special characters omitted], and [special characters omitted] hypernuclei are presented. In an attempt to emphasize the presence of the core-excited states we introduced a novel likelihood approach to particle identification (PID) to serve as an alternative to the commonly used standard hard-cut PID. The new method resulted in almost identical missing mass spectra as obtained by the standard approach. An energy resolution of approximately 400–500 keV (FWHM) has been achieved, an unprecedented value in hypernuclear reaction spectroscopy. For [special characters omitted] the core-excited configuration has been clearly observed with significant statistics. The embedded Λ hyperon increases the excitation energies of the 11B nuclear core by 0.5–1 MeV. The [special characters omitted] spectrum has been observed with significant statistics for the first time. The ground state is bound deeper by roughly 400 keV than currently predicted by theory. Indication for the core-excited doublet, which is unbound in the core itself, is observed. The measurement of [special characters omitted] provides the first study of a d-shell hypernucleus with sub-MeV resolution. Discrepancies of up to 2 MeV between measured and theoretically predicted binding energies are found. Similar disagreement exists when comparing to the [special characters omitted] mirror hypernucleus. Also the core-excited structure observed between the major s-, p- and d-shell Λ orbits is not consistent with the available theoretical calculations. In conclusion, the discrepancies found in this study will provide valuable input for the further development of theoretical models.

Lead oxide-modified TiO2 photocatalyst: tuning light absorption and charge carrier separation by lead oxidation state

Modification of TiO2 with metal oxide nanoclusters such as FeOx, NiOx has been shown to be a promising approach to the design of new photocatalysts with visible light absorption and improved electron–hole separation. To study further the factors that determine the photocatalytic properties of structures of this type, we present in this paper a first principles density functional theory (DFT) investigation of TiO2 rutile(110) and anatase(001) modified with PbO and PbO2 nanoclusters, with Pb2+ and Pb4+ oxidation states. This allows us to unravel the effect of the Pb oxidation state on the photocatalytic properties of PbOx-modified TiO2. The nanoclusters adsorb strongly at all TiO2 surfaces, creating new Pb–O and Ti–O interfacial bonds. Modification with PbO and PbO2 nanoclusters introduces new states in the original band gap of rutile and anatase. However the oxidation state of Pb has a dramatic impact on the nature of the modifications of the band edges of TiO2 and on the electron–hole separation mechanism. PbO nanocluster modification leads to an upwards shift of the valence band which reduces the band gap and upon photoexcitation results in hole localisation on the PbO nanocluster and electron localisation on the surface. By contrast, for PbO2 nanocluster modification the hole will be localised on the TiO2 surface and the electron on the nanocluster, thus giving rise to two different band gap reduction and electron–hole separation mechanisms. We find no crystal structure sensitivity, with both rutile and anatase surfaces showing similar properties upon modification with PbOx. In summary the photocatalytic properties of heterostructures of TiO2 with oxide nanoclusters can be tuned by oxidation state of the modifying metal oxide, with the possibility of a reduced band gap causing visible light activation and a reduction in charge carrier recombination.

Multistabilities and symmetry-broken one-color and two-color states in closely coupled single-mode lasers

We theoretically investigate the dynamics of two mutually coupled, identical single-mode semi-conductor lasers. For small separation and large coupling between the lasers, symmetry-broken one-color states are shown to be stable. In this case the light outputs of the lasers have significantly different intensities while at the same time the lasers are locked to a single common frequency. For intermediate coupling we observe stable symmetry-broken two-color states, where both lasers lase simultaneously at two optical frequencies which are separated by up to 150 GHz. Using a five-dimensional model, we identify the bifurcation structure which is responsible for the appearance of symmetric and symmetry-broken one-color and two-color states. Several of these states give rise to multistabilities and therefore allow for the design of all-optical memory elements on the basis of two coupled single-mode lasers. The switching performance of selected designs of optical memory elements is studied numerically.

Suppression of Hydrogen Emission in a White-light Solar Flare

We present an analysis of an X-class flare that occurred on 11 June 2014 in active region NOAA 12087 using a newly developed high cadence Image
Selector operated by Astronomical Institute in Ondrejov, Czech Republic. This instrument provides spectra in the 350 - 440 nm wavelength range, which
covers the higher order Balmer lines as well as the Balmer jump at 364 nm. However, no detectable increase in these emissions were detected during
the flare, and support observations from SDO/EVE MEGS-B also show that the Lyman line series and recombination continuum were also suppressed,
particularly when compared to an M-class flare that occurred an hour earlier, and two other X-class flares on the preceding day. The X-class flare under
investigation also showed strong white light emission in SDO/HMI data, as well as an extremely hard electron spectrum ( 3.6), and
-ray emission,
from RHESSI data. This unique combination of datasets allows us to conclude that the white light emission from this flare corresponds to a black body
heated by high-energy electrons (and/or ions), as opposed to optical chromospheric emission from hydrogen.

Fruit and vegetable intake and risk of incident of type 2 diabetes: results from the consortium on health and ageing network of cohorts in Europe and the United States (CHANCES)

BACKGROUND/OBJECTIVES: There is limited information to support definitive recommendations concerning the role of diet in the development of type 2 Diabetes mellitus (T2DM). The results of the latest meta-analyses suggest that an increased consumption of green leafy vegetables may reduce the incidence of diabetes, with either no association or weak associations demonstrated for total fruit and vegetable intake. Few studies have, however, focused on older subjects.

SUBJECTS/METHODS: The relationship between T2DM and fruit and vegetable intake was investigated using data from the NIH-AARP study and the EPIC Elderly study. All participants below the age of 50 and/or with a history of cancer, diabetes or coronary heart disease were excluded from the analysis. Multivariate logistic regression analysis was used to calculate the odds ratio of T2DM comparing the highest with the lowest estimated portions of fruit, vegetable, green leafy vegetables and cabbage intake.

RESULTS: Comparing people with the highest and lowest estimated portions of fruit, vegetable or green leafy vegetable intake indicated no association with the risk of T2DM. However, although the pooled OR across all studies showed no effect overall, there was significant heterogeneity across cohorts and independent results from the NIH-AARP study showed that fruit and green leafy vegetable intake was associated with a reduced risk of T2DM OR 0.95 (95% CI 0.91,0.99) and OR 0.87 (95% CI 0.87,0.90) respectively.

CONCLUSIONS: Fruit and vegetable intake was not shown to be related to incident T2DM in older subjects. Summary analysis also found no associations between green leafy vegetable and cabbage intake and the onset of T2DM. Future dietary pattern studies may shed light on the origin of the heterogeneity across populations.European Journal of Clinical Nutrition advance online publication, 17 August 2016; 

Assessing Potential Laser Strike Protection Engineering Control for United States Coast Guard Aircraft

Thesis (Master's)--University of Washington, 2016-06