Determination of maximal Gaussian entanglement achievable by feedback-controlled dynamics

We determine a general upper bound for the steady-state entanglement achievable by continuous feedback for systems of any number of bosonic degrees of freedom. We apply such a bound to the specific case of parametric interactions - the most common practical way to generate entanglement in quantum optics - and single out optimal feedback strategies that achieve the maximal entanglement. We also consider the case of feedback schemes entirely restricted to local operations and compare their performance to the optimal, generally nonlocal, schemes.Comment: 4 pages. Published versio

An analytical and experimental comparison of the flow field of an advanced swept turboprop

An argon ion laser velocimeter with four beams was used to measure the detailed flow-field of an advanced eight blade propeller with 45% of tip sweep in an 8x6 foot supersonic wind tunnel. Data were obtained at a free stream Mach number of 0.8, the design advance ratio of 3.06 and a power coefficient of 1.8. Data are presented for inlet flow, exit flow, flow within the blades and flow slightly outside the blade tips. The data are compared to a lifting line theory. In general, the results of the comparison are considered favorable

Essential oil composition and polar fraction analysis of Tanacetum macrophyllum (Waldst. et Kit.) Schultz Bip.

Tanacetum macrophyllum (Waldst. et Kit.) Schultz Bip, also known as Tansy, is a perennial herbaceous plant belonging to the Asteraceae family. This species is typical of the Balcan area but is punctually spread in other European countries as a rare species [1]. In Italy, it is found mainly within forests [1, 2]. This species is often erroneously confused with Achillea grandifolia Friv. [1, 2]. In this work, a comprehensive phytochemical analysis on the volatile components and polar fraction of T. macrophyllum growing in central Italy was carried out. Flowers and leaves were separately analyzed for the essential oil composition and were characterized by oxygenated monoterpenes (39.4%) and oxygenated sesquiterpenes (28.0%) and sesquiterpene hydrocarbons (39.3%) and oxygenated monoterpenes (25.4%), respectively. The phytochemical analysis conducted on the ethanolic extract of the total aerial parts evidenced the presence of twelve compounds: apigenin, cirsimaritin, apigenin-7-O-glucoside, apigenin-7-O-glucuronide, kaempferol-7-O-glucoside, kaempferol-7-O-glucuronide, 3,5-dicaffeoylquinic acid, 4,5-dicaffeoylquinic acid, chlorogenic acid, shikimic acid, quinic acid and 4-O-β-D-glucopyranosyl-vanillic acid. Most of these compounds were reported for the first time in the species while three of them are new phytochemicals for the Tanacetum genus. The presence of all these compounds provides a phytochemical rationale for the botanical classification of this species and encourages further ethno-pharmacological studies just like for T. parthenium [3]

Optomechanical circuits for nanomechanical continuous variable quantum state processing

We propose and analyze a nanomechanical architecture where light is used to perform linear quantum operations on a set of many vibrational modes. Suitable amplitude modulation of a single laser beam is shown to generate squeezing, entanglement, and state-transfer between modes that are selected according to their mechanical oscillation frequency. Current optomechanical devices based on photonic crystals may provide a platform for realizing this scheme.Comment: 11 pages, 5 figure

Manipulating the quantum information of the radial modes of trapped ions: Linear phononics, entanglement generation, quantum state transmission and non-locality tests

We present a detailed study on the possibility of manipulating quantum information encoded in the "radial" modes of arrays of trapped ions (i.e., in the ions' oscillations orthogonal to the trap's main axis). In such systems, because of the tightness of transverse confinement, the radial modes pertaining to different ions can be addressed individually. In the first part of the paper we show that, if local control of the radial trapping frequencies is available, any linear optical and squeezing operation on the locally defined modes - on single as well as on many modes - can be reproduced by manipulating the frequencies. Then, we proceed to describe schemes apt to generate unprecedented degrees of bipartite and multipartite continuous variable entanglement under realistic noisy working conditions, and even restricting only to a global control of the trapping frequencies. Furthermore, we consider the transmission of the quantum information encoded in the radial modes along the array of ions, and show it to be possible to a remarkable degree of accuracy, for both finite-dimensional and continuous variable quantum states. Finally, as an application, we show that the states which can be generated in this setting allow for the violation of multipartite non-locality tests, by feasible displaced parity measurements. Such a demonstration would be a first test of quantum non-locality for "massive" degrees of freedom (i.e., for degrees of freedom describing the motion of massive particles).Comment: 21 pages; this paper, presenting a far more extensive and detailed analysis, completely supersedes arXiv:0708.085

High intensity X/ γ photon beams for nuclear physics and photonics

In this manuscript we review the challenges of Compton back-scattering sources in advancing photon beam performances in the1−20MeVenergy range, underlining the design criteria bringing tomaximum spectral luminosity and briefly describing the main achieve-ments in conceiving and developing new devices (multi-bunch RF cav-ities and Laser recirculators) for the case of ELI-NP Gamma BeamSystem (ELI-NP-GBS)

Secondary metabolites from Stachys palustris L.

In this work we report the first total analysis of the secondary metabolites from a sample of Stachys palustris L., an herbaceous perennial plant belonging to Lamiaceae, collected in Hungary. The phytochemical analysis, performed by means of classical column chromatography and NMR spectroscopy and Mass spectrometry (MS), allowed us to isolate and identify eight compounds such as verbascoside (1) [1], echinacoside (2) [1], two isoscutellarein derivatives (3, 4) [2,3], chlorogenic acid (5) [3], harpagide (6) [4], 8-O-acetyl-harpagide (7) [4] and monomelittoside (8) [4]. These compounds belong to four different classes of chemical compounds namely phenyl-ethanoid glycosides (PhGs) (compounds 1, 2), flavonoids (compounds 3,4), caffeoyl-quinic acids (compound 5) and iridoids (compounds 6,7 and 8). From a chemosystematic point of view, these compounds are all important: compounds (6) and (7) are considered as the major chemotaxonomic markers of the genus; compound (1) and (8) resulted new constituents in this species and compound (2) is even new in the genus. In addition to this, the co-occurrence of iridoids and PhGs has a chemosystematic importance since it is widely demonstrated their presence in Asterids [1, 3]. Lastly, compounds (3) and (4) such as compounds (5),(6) and (7) have already been found in Stachys species, giving, this way, evidence of a phytochemical pattern perfectly in accordance with those reported in literature for other members of this genus. Nevertheless, it’s worth to underline the fact that compounds (3) and (4), like all isoscutellarein derivatives containing allose, seem to have a restricted distribution in only some genera of Lamiaceae

Secondary metabolites from Stachys palustris L.

In this work we report the first total analysis of the secondary metabolites from a sample of Stachys palustris L., an herbaceous perennial plant belonging to Lamiaceae, collected in Hungary. The phytochemical analysis, performed by means of classical column chromatography and NMR spectroscopy and Mass spectrometry (MS), allowed us to isolate and identify eight compounds such as verbascoside (1) [1], echinacoside (2) [1], two isoscutellarein derivatives (3, 4) [2,3], chlorogenic acid (5) [3], harpagide (6) [4], 8-O-acetyl-harpagide (7) [4] and monomelittoside (8) [4]. These compounds belong to four different classes of chemical compounds namely phenyl-ethanoid glycosides (PhGs) (compounds 1, 2), flavonoids (compounds 3,4), caffeoyl-quinic acids (compound 5) and iridoids (compounds 6,7 and 8). From a chemosystematic point of view, these compounds are all important: compounds (6) and (7) are considered as the major chemotaxonomic markers of the genus; compound (1) and (8) resulted new constituents in this species and compound (2) is even new in the genus. In addition to this, the co-occurrence of iridoids and PhGs has a chemosystematic importance since it is widely demonstrated their presence in Asterids [1, 3]. Lastly, compounds (3) and (4) such as compounds (5),(6) and (7) have already been found in Stachys species, giving, this way, evidence of a phytochemical pattern perfectly in accordance with those reported in literature for other members of this genus. Nevertheless, it’s worth to underline the fact that compounds (3) and (4), like all isoscutellarein derivatives containing allose, seem to have a restricted distribution in only some genera of Lamiaceae

Quantifying decoherence in continuous variable systems

We present a detailed report on the decoherence of quantum states of continuous variable systems under the action of a quantum optical master equation resulting from the interaction with general Gaussian uncorrelated environments. The rate of decoherence is quantified by relating it to the decay rates of various, complementary measures of the quantum nature of a state, such as the purity, some nonclassicality indicators in phase space and, for two-mode states, entanglement measures and total correlations between the modes. Different sets of physically relevant initial configurations are considered, including one- and two-mode Gaussian states, number states, and coherent superpositions. Our analysis shows that, generally, the use of initially squeezed configurations does not help to preserve the coherence of Gaussian states, whereas it can be effective in protecting coherent superpositions of both number states and Gaussian wave packets.Comment: Review article; 36 pages, 19 figures; typos corrected, references adde

Optical implementation and entanglement distribution in Gaussian valence bond states

We study Gaussian valence bond states of continuous variable systems, obtained as the outputs of projection operations from an ancillary space of M infinitely entangled bonds connecting neighboring sites, applied at each of $N$ sites of an harmonic chain. The entanglement distribution in Gaussian valence bond states can be controlled by varying the input amount of entanglement engineered in a (2M+1)-mode Gaussian state known as the building block, which is isomorphic to the projector applied at a given site. We show how this mechanism can be interpreted in terms of multiple entanglement swapping from the chain of ancillary bonds, through the building blocks. We provide optical schemes to produce bisymmetric three-mode Gaussian building blocks (which correspond to a single bond, M=1), and study the entanglement structure in the output Gaussian valence bond states. The usefulness of such states for quantum communication protocols with continuous variables, like telecloning and teleportation networks, is finally discussed.Comment: 15 pages, 6 figures. To appear in Optics and Spectroscopy, special issue for ICQO'2006 (Minsk). This preprint contains extra material with respect to the journal versio