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Author(s): Pascal Weckesser [sup.1] , Fabian Thielemann [sup.1] , Dariusz Wiater [sup.2] , Agata Wojciechowska [sup.2] , Leon Karpa [sup.1] [sup.3] , Krzysztof Jachymski [sup.2] , Michal Tomza [sup.2] , [...], The control of physical systems and their dynamics on the level of individual quanta underpins both fundamental science and quantum technologies. Trapped atomic and molecular systems, neutral.sup.1 and charged.sup.2, are at the forefront of quantum science. Their extraordinary level of control is evidenced by numerous applications in quantum information processing.sup.3,4 and quantum metrology.sup.5,6. Studies of the long-range interactions between these systems when combined in a hybrid atom-ion trap.sup.7,8 have led to landmark results.sup.9-19. However, reaching the ultracold regime--where quantum mechanics dominates the interaction, for example, giving access to controllable scattering resonances.sup.20,21--has so far been elusive. Here we demonstrate Feshbach resonances between ions and atoms, using magnetically tunable interactions between .sup.138Ba.sup.+ ions and .sup.6Li atoms. We tune the experimental parameters to probe different interaction processes--first, enhancing three-body reactions.sup.22,23 and the related losses to identify the resonances and then making two-body interactions dominant to investigate the ion's sympathetic cooling.sup.19 in the ultracold atomic bath. Our results provide deeper insights into atom-ion interactions, giving access to complex many-body systems.sup.24-27 and applications in experimental quantum simulation.sup.28-30. Magnetically tunable interactions between lithium atoms and barium ions are used to demonstrate and probe Feshbach resonances between atoms and ions, which could have applications in the fields of experimental quantum simulation and fundamental physics.

Surveys have revealed many multi-planet systems containing super-Earths and Neptunes in orbits of a few days to a few months (1). There is debate whether in situ assembly (2) or [...]

Characteristics of Fano resonances in metallic arrays of asymmetric dual stripes are theoretically investigated. The structure consists of two perfect metal stripes with unequal sizes in a unit cell. In addition to the total reflection that usually occurs in single-stripe arrays, the dual-stripe arrays exhibit two extra pairs of reflection peaks and dips, which are identified as the Fano resonance with the reflection line shape characterized by a Fano formula. In particular, the peak-dip pair on the high-frequency side is recognized as the high-order Fano resonance, as compared to its counterpart on the low-frequency side. Features of the Fano resonances are further illustrated with the electric field and surface current patterns at the corresponding frequencies. The underlying mechanism of multiple Fano resonances in the dual-stripe arrays is also discussed. OCIS codes: 260.5740, 260.3910.

Based on the analysis of rectangular periodic structures, the resonance frequency band is found to be shifted and broadened from low frequency to high frequency by adjustment of the corresponding structure size. Computer simulation shows that a miniature split-ring resonator can enhance and broaden resonance frequency without changing the stop-band location. According to the theoretical parameters, different experimental samples can be fabricated. The experimental results are generally the same as those predicted theoretically. A comparison of the experimental and theoretical results concluded that a miniature periodic structure broadened the frequency of the stop band and enhanced the resonance frequency, which are important for the study of left-handed materials. [c] 2010 Optical Society of America OCIS codes: 160.0160, 160.4670, 160.4760.

In the present study, binary and triplex DNA molecular beacons, as signaling probes based on a luminol-[H.sub.2][O.sub.2]-horseradish peroxidase (HRP)-fluorescein chemiluminescence resonance energy transfer (CRET) system and structure-switching aptamers for highly sensitive detection of small molecules, are developed using adenosine triphosphate (ATP) as a model analyte to demonstrate the generality of the strategy. This CRET process occurs from donor luminol to acceptor fluorescein, which is oxidized by [H.sub.2][O.sub.2] and catalyzed by HRP. DNA aptamer for ATP is first attached on the surface of magnetic nanoparicles (MNPs). The cDNA linker has an extension that hybridizes with two other DNAs (LumAuNP-DNA and F-DNA) or three other DNAs (HRP-DNA, LumAuNP--DNA, and F-DNA) to fabricate CRET-BMBP-MNP or CRET-TMBP-MNP conjugates that provide the CRET signals. Thus, in the absence of ATP, when the MNPs are removed from the solution, they also take with them the linker DNA and the CRET signal probes, and no CRET signal can be detected. However, when ATP is introduced, a competition for the ATP aptamer between ATP and the cDNA linker occurs. As a result, CRET-BMBP and CRET-TMBP are forced to dissociate from the MNP surface based on the structure switching of the aptamer. The CRET signals are proportional to the concentration of ATP. In order to accelerate the rate of the aptamer structure-switching process, an invader DNA is introduced into the proposed strategy. The present CRET system provides a low detection limit of 1.1 x [10.sup.7] and 3.2 x [10.sup.-7] M for ATP detection by BMBP and TMBP, respectively, which also exhibits a good selectivity for ATP detection. Sample assays of ATP in K562 leukemia cells and 4T1 breast cancer cells confirm the reliability and practicality of the protocol, which reveal a good prospect of this platform for biological sample analysis. 10.1021/ac901759g

We present an optical resonance sensor capable of measurement of refractive index in highly nonhomogeneous materials. Traditional optical resonance sensors fail when the size of particles is comparable with the wavelength (100 nm and larger). Our new nanoengineered design allows incorporation of a highly delocalized mode into a resonance structure. The sensing depth of the device was measured to be l [micro]m, the largest reported in the literature as far as we know, with a quality factor of 500. We demonstrate two applications. OCIS codes: 050.0050, 050.1950, 050.2770, 230.3990, 230.4000, 240.3990.

Drug abuse is a worldwide health concern in which addiction involves activation of the dopaminergic signaling pathway in the brain. Here, we introduce a nanotechnology approach that utilizes gold nanorod-DARPP-32 siRNA complexes (nanoplexes) that target this dopaminergic signaling pathway in the brain. The shift in the localized longitudinal plasmon resonance peak of gold nanorods (GNRs) was used to show their interaction with siRNA. Plasmonic enhanced dark field imaging was used to visualize the uptake of these nanoplexes in dopaminergic neurons in vitro. Gene silencing of the nanoplexes in these cells was evidenced by the reduction in the expression of key proteins (DARPP-32, ERK, and PP-1) belonging to this pathway, with no observed cytotoxicity. Moreover, these nanoplexes were shown to transmigrate across an in vitro model of the blood-brain barrier (BBB). Therefore, these nanoplexes appear to be suited for brain-specific delivery of appropriate siRNA for therapy of drug addiction and other brain diseases. DARPP-32 | dark field imaging | surface plasmon resonance | nanoplexes | blood-brain barrier

The interaction between acoustic resonance and damping controlled fluidelastic instability (FEI) in a normal triangular tube array (P/d = 1.32) has been investigated. The duct acoustics were excited with speakers placed adjacent to the tube array to artificially replicate flow-induced acoustic resonance. The paper deals with the effect on the rms level of tube vibration of three independent parameters: imposed acoustic sound pressure level freestream flow velocity, and structural damping. A fall in the FEI vibration amplitude with increasing sound pressure level in the tube array has been. observed. In addition, the imposed acoustic field delays the onset of damping controlled fluidelastic instability. The effects of flow velocity and structural damping in conjunction with acoustic resonance on the rms of tube displacement are discussed. While the current study has clearly captured the phenomenon of interaction between the fluidelastic motion at approximately 10 Hz and the acoustic field at approximately 1 kHz, it is not apparent what the physical mechanism at work might be. [DOI: 10.1115/1.3006894]

The dynamic instability of doubly curved panels with a centrally located circular cutout, subjected to nonuniform compressive in-plane harmonic edge loading is investigated. The present work deals with the problem of the occurrence of combination resonances in contrast to single (mode) resonances in parametrically excited doubly curved panels with a central circular cutout. The method of multiple scales is used to obtain analytical expressions for the single (mode) and combination resonance instability regions. It is shown that other cases of the combination resonance can be of major importance and yield a significantly enlarged instability region in comparison to the principal instability region. The effects of nonuniform edge loading, centrally located circular cutout, damping, the static, and dynamic load factors on dynamic instability behavior of simply supported doubly curved panels are studied. The results show that under localized edge loading, combination resonance zones are as important as single (mode) resonance zones. The effects of damping show that there is a finite critical value of the dynamic load factor for each instability region below which doubly curved panels cannot become dynamically unstable. A central circular cutout has the destabilizing effect on the dynamic stability behavior of doubly curved panels subjected to nonuniform edge loading. This example of simultaneous excitation of two modes, each oscillating steadily at its own natural frequency, may be of considerable interest in vibration testing of actual structures. CE Database subject headings: Damping; Resonance; Vibration; Panels.

A method to evaluate harmonic contributions at the point of common coupling is presented in this paper. The proposed approach is based on the harmonic current vector method where reference impedances are introduced. Resistance defined at fundamental frequency with measurements is used as the customer-side reference impedance. The presented method allows calculation of harmonic contributions without knowing the actual customer impedances. It also enables better evaluation of the customer and utility harmonic contributions in resonance conditions. The method is verified through a simulation study and with extensive field measurements. Long-term measurements are proposed for determination of harmonic contributions. Index Terms--Harmonic contributions, harmonic current vector method, reference impedances, resonance conditions.

We discuss an experiment on coupled RLC circuits with variable coupling strength. The inductive coupling can be easily varied and measured for different configurations. The experiment allows us to explore the variation of the resonance frequencies as a function of the coupling strength between the oscillators. The system illustrates the effect of eigenfrequency repulsion when an interaction couples different modes of oscillation. The experiment is conceptually simple, and its results can be compared quantitatively with theoretical predictions. [DOI: 10.1119/1.2787017]

Electrical mode stirring in reverberating chambers for electromagnetic compatibility is accomplished by antennas that are loaded by variable reactances. The principle is derived from a network model of the chamber that employs measurable coupling factors. The concept is experimentally confirmed in the gigahertz-range for a 1.92 m x 1.84 m x 2.91 m chamber with four conical antennas placed on one sidewall. One antenna is connected to a generator; the other three antennas are reactively loaded by variable short circuit plungers. The resonances are considerably shifted by varying the reactive loads. Index Terms--Electrical mode stirring, electromagnetic compatibility (EMC), reactively loaded antennas, reverberating chambers.

We report laboratory test results of a long period grating (LPG) that can maintain a constant resonant peak depth over an enhanced tuning range when it is coated with an indium tin oxide (ITO) electrode that has optimized thickness and refractive index. The authors have experimentally demonstrated a LPG coated with ITO that can be tuned in excess of 200 nm with an ambient refractive index change of less than 0.01. To the best of the authors' knowledge, this is the highest sensitivity reported for a LPG to date. In addition to the tuning performance, the resonant peak remains within 1 dB of its maximum depth fbr at least 100 nm of the tuning range. OCIS codes: 060.2280, 230.0230.

A nonparaxial scalar diffraction integral is used to determine numerically the resonance modes of a two-dimensional nearly concentric Fabry-Perot resonator. Numerical examples are provided, and results are compared to those published by Laabs and Friberg [IEEE J. Quantum Electron. 35, 198 (1999)]. Discrepancies are reported and further discussed on the basis of the difference between the solution space supported by the numerical method used here and the one used by Laabs and Friberg. OCIS codes: 050.2230, 120.2230, 350.5500.

Features of resonance power absorption in a lossy dielectric resonator shaped as a rectangular trapezium in a rectangular waveguide are studied. It is found that such a resonator can provide strong absorption (or reflection) of the T[E.sub.10]-mode input from the straight (or inclined) interface port. The maximum absorption is observed when the sum of the coupling coefficients equals unity. Simple formulas relating the scattering and absorption coefficients with the coupling coefficients at the resonance frequency are presented. The physical mechanism of resonance absorption is discussed. Index Terms--Lossy dielectrics, nonsymmetrical couplings, rectangular waveguides, resonance absorption, resonators.

Glancing angle deposition was used to produce ~150-nm-thick silver nanoparticle films, which were evaluated as localized surface plasmon resonance (LSPR) biosensors. The films have a strong extinction peak around 368 nm in air due to LSPR. As the refractive index of the surrounding environment is increased, the extinction peak red-shifts with a linear dependence. The films were functionalized with 11-amino-1-undecanethiol and rabbit immunoglobulin G (rIgG) to allow for the detection of anti-rIgG binding. Binding of biomolecules to the nanoparticle surface increases the local refractive index and results in a red-shifting of the extinction peak. The wavelength shift at varying concentrations of anti-rIgG was measured and fit to the Langmuir isotherm. This yielded approximate values for the saturation response, [DELTA] [[lambda].sub.max] = 29.4 [+ or -] 0.7nm, and the surface confined binding constant, [K.sub.a] = (2.7 [+ or -] 0.3) x [10.sup.6] [M.sup.-1]. The response to nonspecific binding was also investigated.

There is substantial interest in engineering solid supports to achieve functional immobilization of membrane receptors both for investigation of their biological function and for the development of novel biosensors. Three simple and practical strategies for immobilization of a human olfactory receptor carded by nanosomes are presented. The basis of the functionalization of solid gold surfaces is a self-assembled monolayer (SAM) containing biotinyl groups. Biotinyl groups are subsequently used to attach neutravidin and then biotinylated monoclonal antibody directed against the receptor to allow its specific grafting. Surface plasmon resonance technique is implemented for real-time monitoring of step-by-step surface functionalization and, in addition, for testing the functional response of immobilized olfactory receptors. We show that OR1740 is functional when immobilized via a tag attached to its C-terminus, but not via its N-terminus. Finally, we demonstrate that gold surfaces can be patterned by the SAMs tested using microcontact printing. AFM images of immobilized nanosomes onto a patterned surface suggest that small nanosomes flatten and fuse into larger vesicles but do not merge into a continuous layer. The whole study emphasizes the outstanding performances of the BAT/ PEGAT SAM, which could be useful for developing on-a-chip sensor formats for membrane receptor investigations and use.

By means of numerical methods we explore the relevance of the high-order exterior mean motion resonances (MMR) with Neptune that a scattered disk object (SDO) can experience in its diffusion to the Oort cloud. Using a numerical method for estimate the strength of these resonances we show that high-eccentricity or high-inclination resonant orbits should have evident dynamical effects. We investigate the properties of the Kozai mechanism (KM) for non-resonant SDO's and the conditions that generate the KM inside a MMR associated with substantial changes in eccentricity and inclination. We found that the KM inside a MMR is typical for SDO's with Pluto-like or greater inclinations and is generated by the oscillation of w inside the mixed (e, i) resonant terms of the disturbing function. A SDO diffusing to the Oort cloud should experience temporary captures in MMR, preferably of the type 1:N, and when evolving inside a MMR and experiencing the KM it can reach regions where the strength of the resonance drops and consequently there is a possibility of being decoupled from the resonance generating by this way a long-lived high-perihelion scattered disk object (HPSDO). Keywords: Celestial mechanics; Resonances; Trans-neptunian objects

The experimental and theoretical aspects of the interaction of gold nanoshells on a waveguiding structure are studied. The result reveals that the light scattering spectrum of the nanoshells is modified because of the presence of an underlying waveguiding structure.

Hyperfine sublevel correlation spectroscopy and pulsed electron nuclear double resonance were used to elucidate the structure and location of V(IV) ions in heteropolyacid catalysts H4PVMo11O40.

The observation of a resonant, coherent nuclear motion is reported in the elimination reaction of 1,3-dibromopropane (a system with 27 internal degrees of freedom) using femtosecond time-resolved mass spectrometry. The C-Br bond clevage occurs with a reaction time of 2.5 ps and yields the 3-bromopropyl radical, which subsequently reacts to give cyclopropane in 7.5 ps.

The sulfur 1s and oxygen 1s near-edge X-ray absorption fine structure (NEXAFS) spectra of (SO + 20)/Cu(100) are studied by the multiple-scattering cluster (MSC) method. The analysis shows that the Pi orbital breaks into two levels which shift toward higher energy due to the interaction between SO and the substrate.

The wavelength corresponding to the extinction maximum, lambda(sub max), of the localized surface plasmon resonance (LSPR) of silver nanoparticle arrays fabricated by nanosphere lithography (NSL) can be systematically tuned from ~400 nm to 6000 nm. The results demonstrate an unprecedented level of wavelength agility in nanoparticle optical response throughout the visible, near-infrared, and mid-infrared regions of the electromagnetic spectrum.

Research is presented describing the study of 12-mer DNA to determine fluorescence energy transfer rates of single molecules.

This article is an overview of developments in nonlinear chemical kinetics since 1990. Stoichiometric network analysis, correlation metric construction reaction pathways, thermodynamic and stochastic theory of nonlinear systems, and chemical kinetics are discussed.

The electronic properties of multi-open dots structures are found to be modified by small changes to the geometries. A method developed by Bastard and colleagues was used, and the structure was enclosed between two two-dimensional reservoirs. With the changes in coupling between dot and channel states, the transmission through the structure can be be controlled, which would be useful for quantum devices.

Orientation-selected electron nuclear double resonance spectra are derived from iron-linked nitrogens of the d heme of the cytochrome d oxidase complex in frozen solution. Heme d is a high-spin chlorin moiety in the cytochrome d complex situated in Escherichia coli's inner membrane. d heme lacks an axial nitrogen ligand.

Microwave resonant cavity discharges are investigated by the application of perturbation diagnostics. The shift in the frequency of resonance and the cavity quality factor of the resonant cavity are investigated by classical microwave perturbation method. The shift is primarily caused by low electron density discharges. The analysis is applied to the discharges which have electron densities within the limit proposed by the theory of perturbation. The models which discharge homologous individual dielectrics have an exact perturbation analysis.

A simple approach for measuring the extension of the local electromagnetic (EM) field from the surface of a silver nanoparticle by gradually changing the local dielectric environment is presented. The distance dependence of the local EM field associated with 84 plusmn 5nm silver particles is characterized by monitoring spectral shifts in the plasmon resonance due to changes in local dielectric environment, which was controlled by coating the particles with silica layers of various thickness.

The band-gap reduction (BGR) and valence-band splitting in spontaneously ordered GaInAs/InP, has been determined using measures of linear and nonlinear absorption due to bleaching of excitonic resonance. Tilts of the substrate from 2 degrees to 15 degrees towards (111)B were used to obtain samples having various degrees of ordering. The ratio between ordering induced BGR and crystal-field splitting was zeta=1.8 plus or minus 0.4.

A novel bichromophoric system that is capable of undergoing efficient fluorescence resonance energy transfer (FRET) following either two-photon or single photon excitation is presented. The bichronophoric system uses FRET to show that it is possible to utilize high-intensity infrared light to activate molecules.

Research has been conducted on the high-field multifrequency data for the vanadium(III) cation. The detection of EPR resonances is discussed.