ALBERT

Description: Author(s): Cheng Gong, Jiaming Jiang, Chuang Li, Liwei Song, Zhinan Zeng, Jing Miao, Xiaochun Ge, Yinghui Zheng, Ruxin Li, and Zhizhan Xu High-order harmonics were generated with neon gas by using 12-fs midinfrared laser pulses with stabilized carrier-envelope phase (CEP). At some specific CEP, a broad “supercontinuum” of the extreme ultraviolet spectrum can be obtained. Two distinct continuous spectral regimes are found by numerical ... [Phys. Rev. A 85, 033410] Published Thu Mar 08, 2012

Description: Characterization of deep aquifer dynamics using principal component analysis of sequential multilevel data Hydrology and Earth System Sciences, 16, 761-771, 2012 Author(s): D. Kurtzman, L. Netzer, N. Weisbrod, A. Nasser, E. R. Graber, and D. Ronen Two sequential multilevel profiles were obtained in an observation well opened to a 130-m thick, unconfined, contaminated aquifer in Tel Aviv, Israel. While the general profile characteristics of major ions, trace elements, and volatile organic compounds were maintained in the two sampling campaigns conducted 295 days apart, the vertical locations of high concentration gradients were shifted between the two profiles. Principal component analysis (PCA) of the chemical variables resulted in a first principal component which was responsible for ∼60% of the variability, and was highly correlated with depth. PCA revealed three distinct depth-dependent water bodies in both multilevel profiles, which were found to have shifted vertically between the sampling events. This shift cut across a clayey bed which separated the top and intermediate water bodies in the first profile, and was located entirely within the intermediate water body in the second profile. Continuous electrical conductivity monitoring in a packed-off section of the observation well revealed an event in which a distinct water body flowed through the monitored section ( v ∼ 150 m yr −1 ). It was concluded that the observed changes in the profiles result from dominantly lateral flow of water bodies in the aquifer rather than vertical flow. The significance of this study is twofold: (a) it demonstrates the utility of sequential multilevel observations from deep wells and the efficacy of PCA for evaluating the data; (b) the fact that distinct water bodies of 10 to 100 m vertical and horizontal dimensions flow under contaminated sites, which has implications for monitoring and remediation.

Description: Editorial “Advances in Earth observation for water cycle science” Hydrology and Earth System Sciences, 16, 543-549, 2012 Author(s): D. Fernández-Prieto, P. van Oevelen, Z. Su, and W. Wagner

Description: Author(s): A. G. Galstyan, O. Chuluunbaatar, Yu. V. Popov, and B. Piraux We study the effects of nonzero photon momentum on the triply differential cross section (TDCS) for ( γ ,2 e ) processes. Due to the low value of the photon momentum, these effects are weak and manifest only in special kinematical conditions such as the back-to-back emission of the electrons with equal ... [Phys. Rev. A 85, 023418] Published Tue Feb 21, 2012

Description: Author(s): I. Blank, S. Otranto, C. Meinema, R. E. Olson, and R. Hoekstra Single electron transfer and ionization in collisions of N 5+ and Ne 8+ with ground state Na( 3 s ) and laser excited Na * ( 3 p ) are investigated both experimentally and theoretically at collision energies from 1 to 10 keV/amu, which includes the classical orbital velocity of the valence electron. State-sel... [Phys. Rev. A 85, 022712] Published Tue Feb 21, 2012

Description: Author(s): Markus Falkenau, Valentin V. Volchkov, Jahn Rührig, Hannes Gorniaczyk, and Axel Griesmaier Recently, we have experimentally demonstrated a continuous loading mechanism for an optical dipole trap from a guided atomic beam [ M. Falkenau, V. V. Volchkov, J. Rührig, A. Griesmaier and T. Pfau Phys. Rev. Lett. 106 163002 (2011) ]. The observed evolution of the number of atoms and temperature in... [Phys. Rev. A 85, 023412] Published Tue Feb 21, 2012

Description: Author(s): B. Gaire, J. McKenna, M. Zohrabi, K. D. Carnes, B. D. Esry, and I. Ben-Itzhak The dissociation of D 3 + in intense ultrashort laser pulses is investigated using an improved coincidence three-dimensional momentum imaging method that allows clear separation of all fragmentation channels and the determination of the kinetic energy release down to zero. Our results, using 10-fs, 79... [Phys. Rev. A 85, 023419] Published Tue Feb 21, 2012

Description: Author(s): So Takei, Chien-Hung Lin, Brandon M. Anderson, and Victor Galitski We study interacting Rashba-Dresselhaus fermions in two spatial dimensions. First, we present an exact solution to the two-particle bound-state problem of spin-orbit (SO)-coupled fermions for arbitrary Rashba and Dresselhaus SO interactions. An exact molecular-wave function and the Green's function ... [Phys. Rev. A 85, 023626] Published Tue Feb 21, 2012

Description: Author(s): Jianhua Zeng and Boris A. Malomed It has recently been discovered that stabilization of two-dimensional (2D) solitons against the critical collapse in media with cubic nonlinearity by means of nonlinear lattices (NLs) is a challenging problem. We address the one-dimensional (1D) version of the problem, i.e., the nonlinear-Schrödinge... [Phys. Rev. A 85, 023824] Published Tue Feb 21, 2012

Description: Author(s): Yi Yin, H. Wang, M. Mariantoni, Radoslaw C. Bialczak, R. Barends, Y. Chen, M. Lenander, Erik Lucero, M. Neeley, A. D. O'Connell, D. Sank, M. Weides, J. Wenner, T. Yamamoto, J. Zhao, A. N. Cleland, and John M. Martinis A superconducting qubit coupled to a microwave resonator provides a controllable system that enables fundamental studies of light-matter interactions. In the dispersive regime, photons in the resonator exhibit induced frequency and phase shifts which are revealed in the resonator transmission spectr... [Phys. Rev. A 85, 023826] Published Tue Feb 21, 2012

Description: Author(s): Sunkyu Yu, Xianji Piao, and Namkyoo Park In this paper, we investigate the dispersion properties of a multiatomic coupled-resonator optical waveguide (CROW), and show the existence of band-dependent group velocities in its slow-light bands. By including the next-nearest-neighbor coupling terms in a coupled-mode theory (CMT) analysis for th... [Phys. Rev. A 85, 023823] Published Tue Feb 21, 2012

Description: Author(s): Ph. V. Demekhin, B. M. Lagutin, and I. D. Petrov Cross sections and angular distribution parameters of electrons ejected via two-photon ionization of the hydrogen molecule by linearly and circularly polarized light are computed in the exciting-photon energy range of 8–14 eV, which covers the first four optical resonant states of the molecule. Phot... [Phys. Rev. A 85, 023416] Published Tue Feb 21, 2012

Description: Author(s): R. A. Ganeev, V. V. Strelkov, C. Hutchison, A. Zaïr, D. Kilbane, M. A. Khokhlova, and J. P. Marangos We study high-order harmonic generation from a laser-produced tin plasma using 780 and 390 nm, 40 fs, 1 kHz pulses. Varying the chirp of the laser radiation, we observe variation of the harmonic frequency and intensity. The enhanced 16th and 17th harmonics are attributed to the influence of the stro... [Phys. Rev. A 85, 023832] Published Fri Feb 24, 2012

Description: Author(s): Yu-Li Dong, Shi-Qun Zhu, and Wen-Long You The dynamical behavior of a coupled cavity array is investigated when each cavity contains a three-level atom. For the uniform and staggered intercavity hopping, the whole system Hamiltonian can be analytically diagonalized in the subspace of single-atom excitation. The quantum-state transfer along ... [Phys. Rev. A 85, 023833] Published Fri Feb 24, 2012

Description: Author(s): Y. Sherkunov, Vadim V. Cheianov, and Vladimir Fal'ko We investigate the phase diagrams of two-dimensional lattice dipole systems with variable geometry. For bipartite square and triangular lattices with tunable vertical sublattice separation, we find rich phase diagrams featuring a sequence of easy-plane magnetically ordered phases separated by incomm... [Phys. Rev. A 85, 025603] Published Fri Feb 24, 2012

Description: Author(s): Hiroyuki Takeda I theoretically demonstrate the collective population evolution of two-level atoms, based on the mean-field theory. Optical materials with abrupt changes of electromagnetic local densities of states enable steady-state population inversion of two-level atoms which is generally considered impossible.... [Phys. Rev. A 85, 023837] Published Fri Feb 24, 2012

Description: Author(s): Ulrike Herzog We study an optimized measurement which discriminates N mixed quantum states occurring with given prior probabilities. The measurement yields the maximum achievable confidence for each of the N conclusive outcomes, thereby keeping the overall probability of inconclusive outcomes as small as possible... [Phys. Rev. A 85, 032312] Published Mon Mar 12, 2012

Description: Author(s): Daniel P. Joubert It is shown that the density-functional-theory exchange and correlation functionals satisfy 0= γ E h x [ ρ N ]+2 E c γ [ ρ N ]− γ E h x [ ρ N −1 γ ]−2 E c γ [ ρ N −1 γ ]+ 2∫ d 3 r ′ [ ρ N −1 0 ( r )−  ρ N −1 γ ( r )] v 0 ([ ρ N ]; r )+ ∫ d 3 r ′ [ ρ N −1 0 ( r )− ρ N −1 γ ( r )] r · ∇ v 0 ([ ρ N ]; r )+∫ d 3 r ′ ρ N ( r ) r  ·  ∇ v c γ ([ ρ N ]; r ) − ∫ d 3 r ′ ρ N −1 γ ( r ) r · ∇ v c γ ([ ρ N −1 γ ]; r ) − ∫ d 3 r ′ f γ ( r ) r · ∇ v h x c γ ([ ρ N ]; r ... [Phys. Rev. A 85, 032511] Published Mon Mar 12, 2012

Description: Author(s): Muir J. Morrison and Andrei Derevianko The Rydberg blockade mechanism has shown noteworthy promise for scalable quantum computation with neutral atoms. Both qubit states and gate-mediating Rydberg state belong to the same optically trapped atom. The trapping fields, while being essential, induce detrimental decoherence. Here we theoretic... [Phys. Rev. A 85, 033414] Published Mon Mar 12, 2012

Description: Author(s): J. Haestad, A. Murphy, J. D. Wright, and T. J. Morgan D 2 and H 2 Stark recurrence spectra have been measured at scaled energies of ε =−2.3 and ε =−3.2 . An isotope shift in the scaled-action locations of recurrence peaks is found and explained by the increased density of states associated with perturbing rotational series. This reinforces the insight gaine... [Phys. Rev. A 85, 034502] Published Mon Mar 12, 2012

Description: Author(s): Carsten Brée, Ayhan Demircan, and Günter Steinmeyer As previous theoretical results recently revealed, a Kramers-Kronig transform of multiphoton absorption rates allows for a precise prediction on the dispersion of the nonlinear refractive index n 2 in the near infrared. It was shown that this method allows reproduction of recent experimental results ... [Phys. Rev. A 85, 033806] Published Mon Mar 12, 2012

Description: Author(s): F. Arias de Saavedra, F. Mazzanti, J. Boronat, and A. Polls We use microscopic many-body theory to analyze the problem of itinerant ferromagnetism in a repulsive atomic Fermi gas of hard spheres. Using simple arguments we show that the available theoretical predictions for the onset of the ferromagnetic transition predict a transition point at a density ( k F a ... [Phys. Rev. A 85, 033615] Published Mon Mar 12, 2012

Description: Author(s): Chi-Hang Fred Fung, Xiongfeng Ma, H. F. Chau, and Qing-yu Cai Privacy amplification (PA) is an essential postprocessing step in quantum key distribution (QKD) for removing any information an eavesdropper may have on the final secret key. In this paper, we consider delaying PA of the final key after its use in one-time pad encryption and prove its security. We ... [Phys. Rev. A 85, 032308] Published Fri Mar 09, 2012

Description: Author(s): K. M. Dunseath and M. Terao-Dunseath Xu and Shakeshaft [ Phys. Rev. A 84 024701 (2011) ] presented theoretical cross sections for excitation of the 2 s and 2 p states of He + at low collision energies, pointing out in particular the presence of cusps at the excitation threshold. We update their discussion of the comparison between theory ... [Phys. Rev. A 85, 036701] Published Fri Mar 09, 2012

Description: Author(s): Yulian V. Vanne and Alejandro Saenz A theoretical study of the intense-field multiphoton ionization of hydrogenlike systems is performed by solving the time-dependent Dirac equation within the dipole approximation. It is shown that the velocity-gauge results agree to the ones in the length gauge only if the negative-energy states are ... [Phys. Rev. A 85, 033411] Published Fri Mar 09, 2012

Description: Prioritization of water management under climate change and urbanization using multi-criteria decision making methods Hydrology and Earth System Sciences, 16, 801-814, 2012 Author(s): J.-S. Yang, E.-S. Chung, S.-U. Kim, and T.-W. Kim This paper quantifies the transformed effectiveness of alternatives for watershed management caused by climate change and urbanization and prioritizes five options using multi-criteria decision making techniques. The climate change scenarios (A1B and A2) were obtained by using a statistical downscaling model (SDSM), and the urbanization scenario by surveying the existing urban planning. The flow and biochemical oxygen demand (BOD) concentration duration curves were derived, and the numbers of days required to satisfy the environmental flow requirement and the target BOD concentration were counted using the Hydrological Simulation Program-Fortran (HSPF) model. In addition, five feasible alternatives were prioritized by using multi-criteria decision making techniques, based on the driving force-pressure-state-impact-response (DPSIR) framework and cost component. Finally, a sensitivity analysis approach for MCDM methods was conducted to reduce the uncertainty of weights. The result indicates that the most sensitive decision criterion is cost, followed by criteria response, driving force, impact, state and pressure in that order. As it is certain that the importance of cost component is over 0.127, construction of a small wastewater treatment plant will be the most preferred alternative in this application.

Description: Author(s): Jiří Minář, Hugues de Riedmatten, and Nicolas Sangouard We present a quantum repeater scheme based on the recently proposed qubit amplifier [ N. Gisin, S. Pironio and N. Sangouard Phys. Rev. Lett. 105 070501 (2010) ]. It relies on an on-demand entangled-photon-pair source which uses on-demand single-photon sources, linear optical elements, and atomic ens... [Phys. Rev. A 85, 032313] Published Tue Mar 13, 2012

Description: Author(s): M. V. Frolov, N. L. Manakov, A. M. Popov, O. V. Tikhonova, E. A. Volkova, A. A. Silaev, N. V. Vvedenskii, and Anthony F. Starace We present a theoretical model for describing the interaction of an electron, weakly bound in a short-range potential, with an intense, few-cycle laser pulse. General definitions for the differential probability of above-threshold ionization and for the yield of high-order-harmonic generation (HHG) ... [Phys. Rev. A 85, 033416] Published Tue Mar 13, 2012

Description: Author(s): A. O. Lindahl, J. Rohlén, H. Hultgren, I. Yu. Kiyan, D. J. Pegg, C. W. Walter, and D. Hanstorp A collinear beams apparatus has been used to determine photodetachment cross sections for K − in the photon energy range 4.250–4.360 eV. State-selective detection, utilizing a resonance ionization scheme, was applied to measure partial cross sections for those channels which leave the residual K atom... [Phys. Rev. A 85, 033415] Published Tue Mar 13, 2012

Description: Author(s): Zhi-Hai Zhang, Pei Lu, Shiping Feng, and Shi-Jie Yang The effects of disorder on the quantum coherence for many-boson systems are studied in a double-well model. For the ground state, the disorder enhances the quantum coherence. In the deep Mott regime, dynamical evolution reveals periodical collapses and revivals of the quantum coherence, which is rob... [Phys. Rev. A 85, 033617] Published Tue Mar 13, 2012

Description: An integrated uncertainty and ensemble-based data assimilation approach for improved operational streamflow predictions Hydrology and Earth System Sciences, 16, 815-831, 2012 Author(s): M. He, T. S. Hogue, S. A. Margulis, and K. J. Franz The current study proposes an integrated uncertainty and ensemble-based data assimilation framework (ICEA) and evaluates its viability in providing operational streamflow predictions via assimilating snow water equivalent (SWE) data. This step-wise framework applies a parameter uncertainty analysis algorithm (ISURF) to identify the uncertainty structure of sensitive model parameters, which is subsequently formulated into an Ensemble Kalman Filter (EnKF) to generate updated snow states for streamflow prediction. The framework is coupled to the US National Weather Service (NWS) snow and rainfall-runoff models. Its applicability is demonstrated for an operational basin of a western River Forecast Center (RFC) of the NWS. Performance of the framework is evaluated against existing operational baseline (RFC predictions), the stand-alone ISURF and the stand-alone EnKF. Results indicate that the ensemble-mean prediction of ICEA considerably outperforms predictions from the other three scenarios investigated, particularly in the context of predicting high flows (top 5th percentile). The ICEA streamflow ensemble predictions capture the variability of the observed streamflow well, however the ensemble is not wide enough to consistently contain the range of streamflow observations in the study basin. Our findings indicate that the ICEA has the potential to supplement the current operational (deterministic) forecasting method in terms of providing improved single-valued (e.g., ensemble mean) streamflow predictions as well as meaningful ensemble predictions.

Description: Author(s): Dragana M. Jović, Milivoj R. Belić, and Cornelia Denz In a numerical study, we observe Anderson localization of surface modes at the interface between a linear and a nonlinear dielectric medium, containing an optically induced disordered photonic lattice. We discover the threshold for the existence of such localized modes. The influence of Kerr nonline... [Phys. Rev. A 85, 031801] Published Mon Mar 12, 2012

Description: Author(s): Markus Johansson, Marie Ericsson, Kuldip Singh, Erik Sjöqvist, and Mark S. Williamson Global phase factors of topological origin, resulting from cyclic local SU evolution, called topological phases, were first described in [ Phys. Rev. Lett. 90 230403 (2003) ], in the case of entangled qubit pairs. In this paper we investigate topological phases in multiqubit systems as the result of... [Phys. Rev. A 85, 032112] Published Mon Mar 12, 2012

Description: Author(s): Li-Yi Hsu As a physical principle, information causality has thus far only been studied by using bipartite protocols. In this paper, we consider information causality in multireceiver random access codes, in which no receiver can gain any information only from classical communication. To precisely distinguish... [Phys. Rev. A 85, 032115] Published Mon Mar 12, 2012

Description: Author(s): Guillaume Aubrun, Stanisław J. Szarek, and Deping Ye For a system of N identical particles in a random pure state, there is a threshold k 0 = k 0 ( N )∼ N /5 such that two subsystems of k particles each typically share entanglement if k 〉 k 0 , and typically do not share entanglement if k 〈 k 0 . By “random” we mean here uniformly distributed on the sphere of th... [Phys. Rev. A 85, 030302] Published Mon Mar 12, 2012

Description: Author(s): Juho Häppölä, Gábor B. Halász, and Alioscia Hamma We study the structure of the revivals in an integrable quantum many-body system, the transverse field X Y spin chain, after a quantum quench. The time evolutions of the Loschmidt echo, the magnetization, and the single-spin entanglement entropy are calculated. We find that the revival times for all ... [Phys. Rev. A 85, 032114] Published Mon Mar 12, 2012

Description: Author(s): Wojciech Ganczarek, Marek Kuś, and Karol Życzkowski Majorana representation of quantum states by a constellation of n “stars” (points on the sphere) can be used to describe any pure state of a simple system of dimension n +1 or a permutation symmetric pure state of a composite system consisting of n qubits. We analyze the variance of the distribution ... [Phys. Rev. A 85, 032314] Published Wed Mar 14, 2012

Description: Author(s): Vahid Karimipour and Mohammad Hossein Zarei We formulate a quantum formalism for the statistical mechanical models of discretized field theories on lattices and then show that the discrete version of φ 4 theory on 2D square lattice is complete in the sense that the partition function of any other discretized scalar field theory on an arbitrary... [Phys. Rev. A 85, 032316] Published Wed Mar 14, 2012

Description: Author(s): F. Bariani and T. A. B. Kennedy The emission of light from a multiply excited atomic ensemble is examined and it is shown how symmetric (spin-wave) and nonsymmetric states of excitation radiate into spatially separate field modes. This observation has potential application to single-photon generation and spin-wave entanglement, si... [Phys. Rev. A 85, 033811] Published Wed Mar 14, 2012

Description: Author(s): Ashok Ajoy, Rama Koteswara Rao, Anil Kumar, and Pranaw Rungta We propose an iterative algorithm to simulate the dynamics generated by any n -qubit Hamiltonian. The simulation entails decomposing the unitary time evolution operator U (unitary) into a product of different time-step unitaries. The algorithm product-decomposes U in a chosen operator basis by identi... [Phys. Rev. A 85, 030303] Published Wed Mar 14, 2012

Description: Author(s): Vitalie Eremeev, Víctor Montenegro, and Miguel Orszag A theoretical model for driving a two-qubit system to a stable long-lived entanglement is discussed. The entire system is represented by two atoms, initially in ground states and disentangled, each one coupled to a separate cavity with the cavities connected by a fiber. The cavities and fiber exchan... [Phys. Rev. A 85, 032315] Published Wed Mar 14, 2012

Description: Author(s): Luis E. Young-S, S. K. Adhikari, and P. Muruganandam A uniform dilute Bose gas of known density has a universal behavior as the atomic scattering length tends to infinity at unitarity while most of its properties are determined by a universal parameter ξ relating the energies of the noninteracting and unitary gases. The usual mean-field equation is no... [Phys. Rev. A 85, 033619] Published Wed Mar 14, 2012

Description: Author(s): Gao-Ren Wang (王高仁), Ting Xie (谢廷), Wei Zhang (张为), Yin Huang (黄寅), and Shu-Lin Cong (丛书林) We present a theoretical model for describing ultracold atomic collision based on the multichannel quantum-defect theory. An analytical expression for the quantum-defect matrix Y is derived for the truncated 1/ R 6 model potential, and threshold behaviors of the quantum-defect parameters are discussed... [Phys. Rev. A 85, 032706] Published Wed Mar 14, 2012

Description: Accounting for seasonality in a soil moisture change detection algorithm for ASAR Wide Swath time series Hydrology and Earth System Sciences, 16, 773-786, 2012 Author(s): J. Van doninck, J. Peters, H. Lievens, B. De Baets, and N. E. C. Verhoest A change detection algorithm is applied on a three year time series of ASAR Wide Swath images in VV polarization over Calabria, Italy, in order to derive information on temporal soil moisture dynamics. The algorithm, adapted from an algorithm originally developed for ERS scatterometer, was validated using a simple hydrological model incorporating meteorological and pedological data. Strong positive correlations between modelled soil moisture and ASAR soil moisture were observed over arable land, while the correlation became much weaker over more vegetated areas. In a second phase, an attempt was made to incorporate seasonality in the different model parameters. It was observed that seasonally changing surface properties mainly affected the multitemporal incidence angle normalization. When applying a seasonal angular normalization, correlation coefficients between modelled soil moisture and retrieved soil moisture increased overall. Attempts to account for seasonality in the other model parameters did not result in an improved performance.

Description: Author(s): Heongkyu Ju Intrapulse quantum spectral correlation of photon numbers of a femtosecond optical pulse, which propagates a 5-m-long optical fiber, is presented in a matrix format for quantum noise study by numerical calculation. The calculation includes the higher-order optical effects such as intrapulse-stimulat... [Phys. Rev. A 85, 033810] Published Wed Mar 14, 2012

Description: Author(s): T. Morgan, B. O'Sullivan, and Th. Busch [Phys. Rev. A 85, 039904] Published Wed Mar 14, 2012

Description: Author(s): Oleg Zatsarinny and Klaus Bartschat We present triple-differential cross sections for electron-impact ionization of a 3 p electron in Ar. Results from a fully nonperturbative close-coupling formalism using our B -spline R -matrix approach are compared with those from a hybrid distorted-wave plus R -matrix (close-coupling) expansion as wel... [Phys. Rev. A 85, 032708] Published Thu Mar 15, 2012

Description: Author(s): H. M. Price and N. R. Cooper We propose a general method by which experiments on ultracold gases can be used to determine the topological properties of the energy bands of optical lattices, as represented by the map of the Berry curvature across the Brillouin zone. The Berry curvature modifies the semiclassical dynamics and hen... [Phys. Rev. A 85, 033620] Published Thu Mar 15, 2012

Description: Author(s): Leif Ove Hansen, Andreas Hauge, Jan Myrheim, and Per Øyvind Sollid Deciding whether a mixed quantum state is separable or entangled is a difficult problem in general. Separable states are positive under partial transposition [they are positive-partial-transpose (PPT) states], but this simple test does not exclude all entangled states. In order to understand the ent... [Phys. Rev. A 85, 022309] Published Mon Feb 06, 2012

Description: Author(s): J. F. Williams, L. Pravica, and S. N. Samarin In a single free two-valence-electron atom, the motion of the electron spin is a consequence of quantum statistics and the Pauli exclusion principle. Subsequently, during an electron impact exchange excitation from a 1 S 0   M S =0 to a 3 S 1   M S =0 state, the electron spin is “parallel transported” around a ... [Phys. Rev. A 85, 022701] Published Mon Feb 06, 2012

Description: Author(s): Gentaro Watanabe and Harri Mäkelä We present a method for phase and number squeezing in two-mode Bose systems using dissipation. The effectiveness of this method is demonstrated by considering cold Bose gases trapped in a double-well potential. The extension of our formalism to an optical lattice gives control of the phase boundarie... [Phys. Rev. A 85, 023604] Published Mon Feb 06, 2012

Description: Author(s): C.-F. Cheng (程存峰), Y. R. Sun (孙羽), H. Pan (潘虎), J. Wang (王进), A.-W. Liu (刘安雯), A. Campargue, and S.-M. Hu (胡水明) The S (3) electric-quadrupole transition of the (3-0) overtone of molecular hydrogen has been recorded with a continuous-wave cavity ring-down spectrometer and calibrated with sub-megahertz accuracy using a temperature-stabilized Fabry-Pérot interferometer. The collision-induced frequency shift and t... [Phys. Rev. A 85, 024501] Published Mon Feb 06, 2012

Description: Author(s): V. A. Dzuba, V. V. Flambaum, and C. Harabati [Phys. Rev. A 85, 029901] Published Mon Feb 06, 2012

Description: Author(s): Santiago F. Caballero-Benítez and Rosario Paredes We study stationary and dynamical properties of the many-body Landau-Zener dynamics of a Bose quantum fluid confined in two coupled one-dimensional chains by using a many-body generalization recently reported Chen et al. [ Nature Phys. 7 61 (2011) ], within the decoupling approximation and the one-l... [Phys. Rev. A 85, 023605] Published Mon Feb 06, 2012

Description: Author(s): B. Khani, S. T. Merkel, F. Motzoi, Jay M. Gambetta, and F. K. Wilhelm We numerically demonstrate the control of motional degrees of freedom of an ensemble of neutral atoms in an optical lattice with a shallow trapping potential. Taking into account the range of quasimomenta across different Brillouin zones results in an ensemble whose members effectively have inhomoge... [Phys. Rev. A 85, 022306] Published Mon Feb 06, 2012

Description: Author(s): Maxime Boissonneault, A. C. Doherty, F. R. Ong, P. Bertet, D. Vion, D. Esteve, and A. Blais We study the backaction of a driven nonlinear resonator on a multilevel superconducting qubit. Using unitary transformations on the multilevel Jaynes-Cummings Hamiltonian and quantum optics master equation, we derive an analytical model that goes beyond linear response theory. Within the limits of v... [Phys. Rev. A 85, 022305] Published Fri Feb 03, 2012

Description: Physically-based modeling of topographic effects on spatial evapotranspiration and soil moisture patterns through radiation and wind Hydrology and Earth System Sciences, 16, 357-373, 2012 Author(s): M. Liu, A. Bárdossy, J. Li, and Y. Jiang In this paper, simulations with the Soil Water Atmosphere Plant (SWAP) model are performed to quantify the spatial variability of both potential and actual evapotranspiration (ET), and soil moisture content (SMC) caused by topography-induced spatial wind and radiation differences. To obtain the spatially distributed ET/SMC patterns, the field scale SWAP model is applied in a distributed way for both pointwise and catchment wide simulations. An adapted radiation model from r.sun and the physically-based meso-scale wind model METRAS PC are applied to obtain the spatial radiation and wind patterns respectively, which show significant spatial variation and correlation with aspect and elevation respectively. Such topographic dependences and spatial variations further propagate to ET/SMC. A strong spatial, seasonal-dependent, scale-relevant intra-catchment variability in daily/annual ET and less variability in SMC can be observed from the numerical experiments. The study concludes that topography has a significant effect on ET/SMC in the humid region where ET is a energy limited rather than water availability limited process. It affects the spatial runoff generation through spatial radiation and wind, therefore should be applied to inform hydrological model development. In addition, the methodology used in the study can serve as a general method for physically-based ET estimation for data sparse regions.

Description: Author(s): Jérôme Crassous, Axelle Amon, and Jeanne Crassous Differential scattering of left- and right-handed circularly polarized waves is a general property of scattering media lacking space-inversion symmetry. We show in this paper that this scattering difference has remarkable properties in the case of an almost transparent chiral random medium. By tunin... [Phys. Rev. A 85, 023806] Published Tue Feb 07, 2012

Description: The importance of parameter resampling for soil moisture data assimilation into hydrologic models using the particle filter Hydrology and Earth System Sciences, 16, 375-390, 2012 Author(s): D. A. Plaza, R. De Keyser, G. J. M. De Lannoy, L. Giustarini, P. Matgen, and V. R. N. Pauwels The Sequential Importance Sampling with Resampling (SISR) particle filter and the SISR with parameter resampling particle filter (SISR-PR) are evaluated for their performance in soil moisture assimilation and the consequent effect on baseflow generation. With respect to the resulting soil moisture time series, both filters perform appropriately. However, the SISR filter has a negative effect on the baseflow due to inconsistency between the parameter values and the states after the assimilation. In order to overcome this inconsistency, parameter resampling is applied along with the SISR filter, to obtain consistent parameter values with the analyzed soil moisture state. Extreme parameter replication, which could lead to a particle collapse, is avoided by the perturbation of the parameters with white noise. Both the modeled soil moisture and baseflow are improved if the complementary parameter resampling is applied. The SISR filter with parameter resampling offers an efficient way to deal with biased observations. The robustness of the methodology is evaluated for 3 model parameter sets and 3 assimilation frequencies. Overall, the results in this paper indicate that the particle filter is a promising tool for hydrologic modeling purposes, but that an additional parameter resampling may be necessary to consistently update all state variables and fluxes within the model.

Description: Author(s): Adán Cabello [Phys. Rev. A 85, 029903] Published Thu Feb 09, 2012

Description: Author(s): D. Valente, S. Portolan, G. Nogues, J. P. Poizat, M. Richard, J. M. Gérard, M. F. Santos, and A. Auffèves We theoretically investigate signatures of stimulated emission at the single-photon level for a two-level atom interacting with a one-dimensional light field. We consider the transient regime where the atom is initially excited, and the steady-state regime where the atom is continuously driven with ... [Phys. Rev. A 85, 023811] Published Thu Feb 09, 2012

Description: Author(s): A. Dot, A. Borne, B. Boulanger, K. Bencheikh, and J. A. Levenson We present a quantum theoretical analysis of triple photons generated by a phase-matched third-order nonlinear process in a KTP crystal in a weak-interaction regime. We show that the quantum properties of the triple photons can be brought to light through optical second- and third-order sum frequenc... [Phys. Rev. A 85, 023809] Published Thu Feb 09, 2012

Description: Technical Note: Analytical sensitivity analysis of a two parameter recursive digital baseflow separation filter Hydrology and Earth System Sciences, 16, 451-455, 2012 Author(s): K. Eckhardt A sensitivity analysis for a well-established baseflow separation technique, a two parameter recursive digital filter, is presented. The sensitivity of the calculated baseflow index to errors or uncertainties of the two filter parameters and of the initial baseflow value is analytically ascertained. It is found that the influence of the initial baseflow value is negligible for long time series. The propagation of errors or uncertainties of the two filter parameters into the baseflow index is expressed by a dimensionless sensitivity index, the ratio between the relative error of the baseflow index and the relative error of the respective parameter. Representative index values are derived by application of the resulting equations to 65 North American catchments. In the mean the parameter a , the recession constant, has a stronger influence on the calculated baseflow index than the second filter parameter BFI max . This is favourable in that a can be determined by a recession analysis and therefore should be less uncertain. Whether this finding also applies for a specific catchment can easily be checked by means of the derived equations.

Description: Author(s): Stefan Riedl, Matthias Lettner, Christoph Vo, Simon Baur, Gerhard Rempe, and Stephan Dürr A scheme based on electromagnetically induced transparency is used to store light in a Bose-Einstein condensate. In this process, a photonic polarization qubit is stored in atomic Zeeman states. The performance of the storage process is characterized and optimized. The average process fidelity is 1.... [Phys. Rev. A 85, 022318] Published Mon Feb 13, 2012

Description: Author(s): Zhen-Kai Lu and G. V. Shlyapnikov We study Fermi-liquid properties of a weakly interacting two-dimensional gas of single-component fermionic polar molecules with dipole moments d oriented perpendicularly to the plane of their translational motion. This geometry allows the minimization of inelastic losses due to chemical reactions fo... [Phys. Rev. A 85, 023614] Published Mon Feb 13, 2012

Description: Author(s): Wei-Chao Jiang, Oleg I. Tolstikhin, Liang-You Peng, and Qihuang Gong The physical origin and properties of quasistationary static-field-induced states (SFISs) are discussed. SFISs can be supported by a combination of any atomic or molecular potential and an external static electric field and do not have counterparts in the absence of the field. A resonant tunneling i... [Phys. Rev. A 85, 023404] Published Mon Feb 13, 2012

Description: Author(s): Ali Saif M. Hassan, Behzad Lari, and Pramod S. Joag Dakic, Vedral, and Brukner [ B. Dakic, V. Vedral and Č. Brukner Phys. Rev. Lett. 105 190502 (2010) ] gave a geometric measure of quantum discord in a bipartite quantum state as the distance of the state from the closest classical quantum (or zero discord) state and derived an explicit formula for a ... [Phys. Rev. A 85, 024302] Published Mon Feb 13, 2012

Description: Author(s): J. S. Borbely, R. van Rooij, S. Knoop, and W. Vassen We have experimentally studied the magnetic-field dependence of the decay of a Bose-Einstein condensate of metastable 4 He atoms confined in an optical dipole trap, for atoms in the m =+1 and m =−1 magnetic substates, and up to 450 G. Our measurements confirm longstanding calculations of the two-body l... [Phys. Rev. A 85, 022706] Published Tue Feb 14, 2012

Description: Author(s): Hong-Keun Kim, M. S. Schöffler, S. Houamer, O. Chuluunbaatar, J. N. Titze, L. Ph. H. Schmidt, T. Jahnke, H. Schmidt-Böcking, A. Galstyan, Yu. V. Popov, and R. Dörner We have measured the electron-transfer process in fast collisions (630–1200 keV/u) of protons with helium, which is dependent on the projectile scattering angle and the final electronic state. The fully differential data accompanied by theoretical second-order perturbation theory allow a detailed in... [Phys. Rev. A 85, 022707] Published Tue Feb 14, 2012

Description: Author(s): Yuanxing Liu, Yunquan Liu, and Qihuang Gong We propose a dynamic pump-control scheme to manipulate the molecular predissociation process of NaI using two color few-cycle laser pulses. We excite the NaI molecule with a pump pulse (648 nm, 35 fs) and employ another control laser pulse (7.53 μm, 50 fs) to modify the molecular potential energy su... [Phys. Rev. A 85, 023406] Published Tue Feb 14, 2012

Description: Author(s): Tomohiko Aioi, Tsuyoshi Kadokura, and Hiroki Saito The dynamics of a vortex dipole in a quasi-two-dimensional two-component Bose-Einstein condensate is investigated. A vortex dipole is shown to penetrate the interface between the two components when the incident velocity is sufficiently large. A vortex dipole can also disappear or disintegrate at th... [Phys. Rev. A 85, 023618] Published Tue Feb 14, 2012

Description: Author(s): Zhi Lin, Jun Zhang, and Ying Jiang In this paper, we investigate systematically the Mott-insulator–superfluid quantum phase transitions for ultracold scalar bosons in triangular, hexagonal, and Kagomé optical lattices. With the help of the field-theoretical effective potential, by treating the hopping term in the Bose-Hubbard model a... [Phys. Rev. A 85, 023619] Published Tue Feb 14, 2012

Description: Author(s): Dmitry Borzov, Mohammad S. Mashayekhi, Shizhong Zhang, Jun-Liang Song, and Fei Zhou In this paper, we explore the nature of three-dimensional Bose gases at large positive scattering lengths via resummation of dominating processes involving a minimum number of virtual atoms. We focus on the energetics of the nearly fermionized Bose gases beyond the usual dilute limit. We also find t... [Phys. Rev. A 85, 023620] Published Tue Feb 14, 2012

Description: Author(s): S. Knoop, J. S. Borbely, R. van Rooij, and W. Vassen We have studied the decay of a Bose-Einstein condensate (BEC) of metastable helium atoms in an optical dipole trap. In the regime where two- and three-body losses can be neglected we show that the Bose-Einstein condensate and the thermal cloud show fundamentally different decay characteristics. The ... [Phys. Rev. A 85, 025602] Published Tue Feb 14, 2012

Description: Author(s): Jan Peřina, Jr., Martin Hamar, Václav Michálek, and Ondřej Haderka The measurement of photon-number statistics of fields composed of photon pairs, generated in spontaneous parametric down-conversion and detected by an intensified charge-coupled device (iCCD) camera, is described. Final quantum detection efficiencies, electronic noises, finite numbers of detector pi... [Phys. Rev. A 85, 023816] Published Tue Feb 14, 2012

Description: Investigating riparian groundwater flow close to a losing river using diurnal temperature oscillations at high vertical resolution Hydrology and Earth System Sciences, 16, 473-487, 2012 Author(s): T. Vogt, M. Schirmer, and O. A. Cirpka River-water infiltration is of high relevance for hyporheic and riparian groundwater ecology as well as for drinking water supply by river-bank filtration. Heat has become a popular natural tracer to estimate exchange rates between rivers and groundwater. However, quantifying flow patterns and velocities is impeded by spatial and temporal variations of exchange fluxes, insufficient sensors spacing during field investigations, or simplifying assumptions for analysis or modeling such as uniform flow. The objective of this study is to investigate lateral shallow groundwater flow upon river-water infiltration at the shoreline of the riverbed and in the adjacent riparian zone of the River Thur in northeast Switzerland. Here we have applied distributed temperature sensing (DTS) along optical fibers wrapped around tubes to measure high-resolution vertical temperature profiles of the unsaturated zone and shallow riparian groundwater. Diurnal temperature oscillations were tracked in the subsurface and analyzed by means of dynamic harmonic regression to extract amplitudes and phase angles. Subsequent calculations of amplitude attenuation and time shift relative to the river signal show in detail vertical and temporal variations of heat transport in shallow riparian groundwater. In addition, we apply a numerical two-dimensional heat transport model for the unsaturated zone and shallow groundwater to obtain a better understanding of the observed heat transport processes in shallow riparian groundwater and to estimate the groundwater flow velocity. Our results show that the observed riparian groundwater temperature distribution cannot be described by uniform flow, but rather by horizontal groundwater flow velocities varying over depth. In addition, heat transfer of diurnal temperature oscillations from the losing river through shallow groundwater is influenced by thermal exchange with the unsaturated zone. Neglecting the influence of the unsaturated zone would cause biased interpretation and underestimation of groundwater flow velocities. The combination of high resolution field data and modeling shows the complex hydraulic and thermal processes occurring in shallow riparian groundwater close to losing river sections as well as potential errors sources for interpreting diurnal temperature oscillations in such environments.

Description: Author(s): Ville Pietilä, David Pekker, Yusuke Nishida, and Eugene Demler We study nonequilibrium dynamics of ultracold two-component Fermi gases in low-dimensional geometries after the interactions are quenched from a weakly interacting to a strongly interacting regime. We develop a T -matrix formalism that takes into account the interplay between Pauli blocking and tight... [Phys. Rev. A 85, 023621] Published Tue Feb 14, 2012

Description: Author(s): Dmitry L. Dorofeev, Sergei V. Elfimov, and Boris A. Zon This paper is dedicated to the implementation of a generalized approach for calculating quantum defects in high Rydberg states of polar molecules with an account for the dipole moment of the molecular core and l uncoupling of the Rydberg electron. Adiabatic (Born-Oppenheimer) and nonadiabatic (inver... [Phys. Rev. A 85, 022509] Published Tue Feb 14, 2012

Description: Author(s): Xiaoling Cui We present exact solutions of a two-body problem for spin- 1/2 fermions with isotropic spin-orbit (SO) coupling and interacting with an arbitrary short-range potential. We find that in each partial-wave scattering channel, the parametrization of a two-body wave function at short interparticle distanc... [Phys. Rev. A 85, 022705] Published Tue Feb 14, 2012

Description: Author(s): Haruhide Miyagi, Toru Morishita, and Shinichi Watanabe We develop an efficient numerical procedure for solving the scattering problem on one-electron diatomic molecules in the fixed-nuclei approximation. For this purpose, we use the R -matrix propagation method together with the discrete variable representation method in prolate spheroidal coordinates. T... [Phys. Rev. A 85, 022708] Published Wed Feb 15, 2012

Description: Hydrogeology and hydrogeochemistry of an alkaline volcanic area: the NE Mt. Meru slope (East African Rift – Northern Tanzania) Hydrology and Earth System Sciences, 16, 529-541, 2012 Author(s): G. Ghiglieri, D. Pittalis, G. Cerri, and G. Oggiano The objective of this study is to analyze the geochemical conditions associated with the presence of fluoride (F − ) in the groundwater of an area of Northern Tanzania. The studied aquifers are composed of volcanic rocks such as phonolitic and nephelinitic lavas, basalts, lahars of various ages and mantling ash. Sedimentary rocks consisting of fine-grained alluvial and lacustrine deposits occur as well. Samples collected from springs, borehole and surface water, during two monitoring surveys, were analyzed for the various physico-chemical and isotopic parameters. The geochemical composition of water is typically sodium bicarbonate. High values of F − (up to 68 mg l −1 ) were recorded. The highest values of fluoride agreed with the highest values of pH, sodium and bicarbonate. Dissolution of major ions, exchange processes and precipitation of Ca 2+ from super-saturated solutions joined with the local permeability and hydraulic gradients, control the fluoride mobilization and the contamination of the area.

Description: Estimation of soil redistribution rates due to snow cover related processes in a mountainous area (Valle d'Aosta, NW Italy) Hydrology and Earth System Sciences, 16, 517-528, 2012 Author(s): E. Ceaglio, K. Meusburger, M. Freppaz, E. Zanini, and C. Alewell Mountain areas are widely affected by soil erosion, which is generally linked to runoff processes occurring in the growing season and snowmelt period. Also processes like snow gliding and full-depth snow avalanches may be important factors that can enhance soil erosion, however the role and importance of snow movements as agents of soil redistribution are not well understood yet. The aim of this study was to provide information on the relative importance of snow related processes in comparison to runoff processes. In the study area, which is an avalanche path characterized by intense snow movements, soil redistribution rates were quantified with two methods: (i) by field measurements of sediment yield in an avalanche deposition area during 2009 and 2010 winter seasons; (ii) by caesium-137 method, which supplies the cumulative net soil loss/gain since 1986, including all the soil erosion processes. The snow related soil accumulation estimated with data from the deposit area (27.5 Mg ha −1 event −1 and 161.0 Mg ha −1 event −1 ) was not only higher than the yearly sediment amounts, reported in literature, due to runoff processes, but it was even more intense than the yearly total deposition rate assessed with 137 Cs (12.6 Mg ha −1 yr −1 ). The snow related soil erosion rates estimated from the sediment yield at the avalanche deposit area (3.7 Mg ha −1 and 20.8 Mg ha −1 ) were greater than the erosion rates reported in literature and related to runoff processes; they were comparable to the yearly total erosion rates assessed with the 137 Cs method (13.4 Mg ha −1 yr −1 and 8.8 Mg ha −1 yr −1 ). The 137 Cs method also showed that, where the ground avalanche does not release, the erosion and deposition of soil particles from the upper part of the basin was considerable and likely related to snow gliding. Even though the comparison of both the approaches is linked to high methodological uncertainties, mainly due to the different spatial and temporal scales considered, we still can deduce, from the similarity of the erosion rates, that soil redistribution in this catchment is driven by snow movement, with a greater impact in comparison to the runoff processes occurring in the snow-free season. Nonetheless, the study highlights that soil erosion processes due to the snow movements should be considered in the assessment of soil vulnerability in mountain areas, as they significantly determine the pattern of soil redistribution.

Description: Author(s): Yu-Chun Wu and Marek Żukowski A technique, which we call homogenization, is applied to transform Clauser and Horne- (CH)-type Bell inequalities that contain lower-order correlations into CH, Shimony, and Holt- (CHSH)-type Bell inequalities, which are defined for highest-order correlation functions. A homogenization leads to ineq... [Phys. Rev. A 85, 022119] Published Tue Feb 21, 2012

Description: Author(s): R. E. Wagner, M. R. Ware, E. V. Stefanovich, Q. Su, and R. Grobe We use a one-dimensional model system to compare the predictions of two different yardsticks to compute the position of a particle from its quantum field theoretical state. Based on the first yardstick (defined by the Newton-Wigner position operator), the spatial density can be arbitrarily narrow, a... [Phys. Rev. A 85, 022121] Published Tue Feb 21, 2012

Description: Author(s): Jost Henkel, Manfred Lein, Volker Engel, and Ingo Dreissigacker By solving the time-dependent Schrödinger equation for atoms in short laser pulses of different polarizations, it is shown that in strong-field ionization without rescattering, the lateral width of the electron-momentum distribution corresponds adiabatically to the instantaneous laser field on a sub... [Phys. Rev. A 85, 021402] Published Tue Feb 21, 2012

Description: Author(s): O. V. Andreev, D. A. Glazov, A. V. Volotka, V. M. Shabaev, and G. Plunien The rigorous calculation of the vacuum-polarization screening corrections to the hyperfine splitting in Li-like bismuth is presented. The two-electron diagrams with electric and magnetic vacuum-polarization loops are evaluated to all orders in α Z , including the Wichmann-Kroll contributions. This imp... [Phys. Rev. A 85, 022510] Published Tue Feb 21, 2012

Description: Author(s): Liang Cui, Xiaoying Li, and Ningbo Zhao The photonic crystal fiber (PCF) is one of the excellent media for generating photon pairs via spontaneous four-wave mixing. Here we study how the inhomogeneity of PCFs affect the spectral properties of photon pairs from both the theoretical and experimental aspects. The theoretical model shows that... [Phys. Rev. A 85, 023825] Published Tue Feb 21, 2012

Description: Author(s): M. Hamamda, M. Boustimi, F. Correia, J. Baudon, T. Taillandier-Loize, G. Dutier, F. Perales, and M. Ducloy A promising technique of atom slowing is proposed. It is based upon the dispersive interaction of atoms with optical potential pulses generated by a far-off-resonance standing wave modulated in time. Each pulse reduces the velocity by a small amount. By repeating the process thousands of times, the ... [Phys. Rev. A 85, 023417] Published Tue Feb 21, 2012

Description: Author(s): Thomas Bourdel We study superfluid transitions in bidimensional (2D) and tridimensional (3D) disordered and interacting Bose gases. We work in the limit of long-range correlated disorder such that it can be treated in the local density approximation. We present superfluid transition curves in both the disorder-tem... [Phys. Rev. A 86, 063626] Published Fri Dec 21, 2012

Description: Author(s): V. M. Bastidas, C. Emary, G. Schaller, and T. Brandes We establish a set of nonequilibrium quantum phase transitions in the Ising model driven under monochromatic nonadiabatic modulation of the transverse field. We show that besides the Ising-like critical behavior, the system exhibits an anisotropic transition which is absent in equilibrium. The noneq... [Phys. Rev. A 86, 063627] Published Fri Dec 21, 2012

Description: Author(s): M. Strebel, T.-O. Müller, B. Ruff, F. Stienkemeier, and M. Mudrich Elastic scattering cross sections are measured for lithium atoms colliding with rare-gas atoms and SF 6 molecules at tunable relative velocities down to ∼50 m/s. Our scattering apparatus combines a velocity-tunable molecular beam with a magneto-optic trap which provides an ultracold cloud of lithium ... [Phys. Rev. A 86, 062711] Published Fri Dec 21, 2012

Description: Author(s): A. G. Radnaev, C. J. Campbell, and A. Kuzmich We excite the 717-nm electric quadrupole 6 D 3/2 ↔ 7 S 1/2 transition in a laser-cooled 232 Th 3+ ion crystal. The transition frequency and the lifetime of the metastable 7 S 1/2 level are measured to be 417 845 964(30) MHz and 0.60(7) s, respectively. We subsequently employ the 7 S 1/2 level to drive the ion... [Phys. Rev. A 86, 060501] Published Wed Dec 26, 2012

Description: Author(s): V. Semin, I. Sinayskiy, and F. Petruccione The strong system-bath correlation is a typical initial condition in many condensed matter and some quantum optical systems. Here, the dynamics of a spin interacting with a spin bath through an intermediate spin are studied. Initial correlations between the spin and the intermediate spin are taken i... [Phys. Rev. A 86, 062114] Published Wed Dec 26, 2012

Description: Author(s): Christina V. Kraus and Tobias J. Osborne We extend the time-dependent variational principle to the setting of dissipative dynamics. This provides a locally optimal (in time) approximation to the dynamics of any Lindblad equation within a given variational manifold of mixed states. In contrast to the pure-state setting, there is no canonica... [Phys. Rev. A 86, 062115] Published Wed Dec 26, 2012

Description: Author(s): Sergio Cordero and Gastón García–Calderón The short-time behavior of quantum decay of an unstable state initially located within an interaction region of finite range is investigated using a resonant expansion of the survival amplitude. It is shown that in general the short-time behavior of the survival probability S ( t ) has a dependence on ... [Phys. Rev. A 86, 062116] Published Wed Dec 26, 2012

Description: Author(s): Derek Harland, M. J. Everitt, Kae Nemoto, T. Tilma, and T. P. Spiller We present a quasiprobability distribution function for ensembles of spin-half particles or qubits that has many properties in common with Wigner's original function for systems of continuous variables. We show that this function provides clear and intuitive graphical representation of a wide variet... [Phys. Rev. A 86, 062117] Published Wed Dec 26, 2012

Description: Author(s): Gastón García-Calderón and Alberto Hernández-Maldonado We consider an exact analytical solution to the time-dependent Schrödinger equation with cutoff initial conditions (quantum shutter setup) to show that in such a case the delay time in the dynamics of resonant tunneling near resonance arises from an interference effect of the quantum transients of t... [Phys. Rev. A 86, 062118] Published Wed Dec 26, 2012

Description: Author(s): J. M. Matera, R. Rossignoli, and N. Canosa We examine the evaluation of entanglement measures in weakly correlated Gaussian states. It is shown that they can be expressed in terms of the singular values of a particular block of the generalized contraction matrix. This result enables us to obtain in a simple way asymptotic expressions and rel... [Phys. Rev. A 86, 062324] Published Wed Dec 26, 2012

Description: Author(s): Denis Rosset, Raphael Ferretti-Schöbitz, Jean-Daniel Bancal, Nicolas Gisin, and Yeong-Cherng Liang Reliable and well-characterized quantum resources are indispensable ingredients in quantum information processing. Typically, in a realistic characterization of these resources, apparatuses come with intrinsic uncertainties that can manifest themselves in the form of systematic errors. While systema... [Phys. Rev. A 86, 062325] Published Wed Dec 26, 2012