cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Reversible spin-optical interface in luminescent organic radicals
Creators: name: Gorgon, Sebastian
name: Lv, Kuo
name: Grüne, Jeannine
name: Drummond, Bluebell H.
name: Myers, William K.
name: Londi, Giacomo
name: Ricci, Gaetano
name: Valverde, Danillo
name: Tonnelé, Claire
name: Murto, Petri
name: Romanov, Alexander S.
name: Casanova, David
name: Dyakonov, Vladimir
name: Sperlich, Andreas
name: Beljonne, David
name: Olivier, Yoann
name: Li, Feng
name: Friend, Richard H.
name: Evans, Emrys W.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Molecules present a versatile platform for quantum information science, and are candidates for sensing and computation applications. Robust spin-optical interfaces are key to harnessing the quantum resources of materials. To date, carbon-based candidates have been non-luminescent, which prevents optical read-out. Here we report the first organic molecules displaying both efficient luminescence and near-unity generation yield of high-spin multiplicity excited states. This is achieved by designing an energy resonance between emissive doublet and triplet levels, here on covalently coupled tris(2,4,6-trichlorophenyl) methyl-carbazole radicals (TTM-1Cz) and anthracene. We observe the doublet photoexcitation delocalise onto the linked acene within a few picoseconds and subsequently evolve to a pure high spin state (quartet for monoradicals, quintet for biradical) of mixed radical-triplet character near 1.8 eV. These high-spin states are coherently addressable with microwaves even at 295 K, with optical read-out enabled by intersystem crossing to emissive states. Furthermore, for the biradical, on return to the ground state the previously uncorrelated radical spins either side of the anthracene show strong spin correlation. Our approach simultaneously supports a high efficiency of initialisation, spin manipulations and light-based read-out at room temperature. The integration of luminescence and high-spin states creates an organic materials platform for emerging quantum technologies.
Bound states in string nets
Creators: name: Schulz, M. D.
name: Dusuel, S.
name: Vidal, J.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Theory (hep-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We discuss the emergence of bound states in the low-energy spectrum of the string-net Hamiltonian in the presence of a string tension. In the ladder geometry, we show that a single bound state arises either for a finite tension or in the zero-tension limit depending on the theory considered. In the latter case, we perturbatively compute the binding energy as a function of the total quantum dimension. We also address this issue in the honeycomb lattice where the number of bound states in the topological phase depends on the total quantum dimension. Finally, the internal structure of these bound states is analyzed in the zero-tension limit.
description: 5 pages, 3 figures, published version
Amtliche Mitteilungen der Universität Dortmund Nr. 08/81
Creators: name: (:Unkn) Unknown
Publisher: name: Universität Dortmund
Year: 1981
Subjects: subject: 080

description: Ordnung der Ersten Staatsprüfungen für Lehrämter an Schulen (Lehramtsprüfungsordnung I - LPO I) vom 22. Juli 1981
description: Amtliche Mitteilungen der Universität Dortmund ; 8, 1981
Kitaev materials beyond iridates: order by quantum disorder and Weyl magnons in rare-earth double perovskites
Creators: name: Li, Fei-Ye
name: Li, Yao-Dong
name: Yu, Yue
name: Paramekanti, Arun
name: Chen, Gang
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Motivated by the experiments on the rare-earth double perovskites, we propose a generalized Kitaev-Heisenberg model to describe the generic interaction between the spin-orbit-entangled Kramers' doublets of the rare-earth moments. We carry out a systematic analysis of the mean-field phase diagram of this new model. In the phase diagram, there exist large regions with a continuous U(1) or O(3) degeneracy. Since no symmetry of the model protects such a continuous degeneracy, we predict that the quantum fluctuation lifts the continuous degeneracy and favors various magnetic orders in the phase diagram. From this order by quantum disorder mechanism, we further predict that the magnetic excitations of the resulting ordered phases are characterized by nearly gapless pseudo-Goldstone modes. We find that there exist Weyl magnon excitations for certain magnetic orders. We expect our prediction to inspire further study of Kitaev physics, the order by quantum disorder phenomenon and topological spin wave modes in the rare-earth magnets and the systems alike.
description: 8 pages, 7 figures, 1 table, update author list, to be published in PhysRevB
Extracting temperature and transverse flow by fitting transverse mass spectra and HBT radii together
Creators: name: He, Ronghua
name: Qian, Jing
name: Chen, Jianyi
name: Wu, Qingxin
name: Huo, Lei
Publisher: name: arXiv
Year: 2016
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Single particle transverse mass spectra and HBT radii of identical pion and identical kaon are analyzed with a blast-wave parametrization under the assumptions local thermal equilibrium and transverse expansion. Under the assumptions, temperature parameter $T$ and transverse expansion rapidity $ρ$ are sensitive to the shapes of transverse mass $m_\text T$ spectrum and HBT radius $R_\text{s}(K_\text T)$. Negative and positive correlations between $T$ and $ρ$ are observed by fitting $m_\text{T}$ spectrum and HBT radius $R_\text s (K_\text T)$, respectively. For a Monte Carlo simulation using the blast-wave function, $T$ and $ρ$ are extracted by fitting $m_T$ spectra and HBT radii together utilizing a combined optimization function $χ^2$. With this method, $T$ and $ρ$ of the Monte Carlo sources can be extracted. Using this method for A Multi-Phase Transport model (AMPT) at RHIC energy, the differences of $T$ and $ρ$ between pion and kaon are observed obviously, and the tendencies of $T$ and $ρ$ vs collision energy $\sqrt{s_\text{NN}}$ are similar with the results extracted directly from the AMPT model.
description: 14 pages, 5 figures
Low scale left-right-right-left symmetry
Creators: name: Abbas, Gauhar
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We propose an effective left-right-right-left model with a parity breaking scale around a few TeV. One of the main achievements of the model is that the mirror fermions as well as the mirror gauge sector simultaneously could be at TeV scale. It is shown that the most dangerous quadratic divergence of the SM Higgs boson involving the top quark in the loop is naturally suppressed, and begins at three loop. The model postpones the fine-tuning of the mass of the SM Higgs boson up to a sufficiently high scale. The model explains the smallness of the neutrino masses whether they are Dirac or Majorana. Furthermore, the strong $CP$ phase is zero in this model.
description: version published in Phys. Rev. D
Far-off-resonance averaging of dipolar interactions in solids
Creators: name: Böhmer, Roland
name: Chang, I.
name: Diezemann, G.
name: Hinze, G.
name: Sillescu, H.
Publisher: name: Academic Press
Year: 1997
Subjects: subject: 530

description: The far-off-resonance performance of several line-narrowing sequences is investigated. Both theoretically and experimentally, it is found that transverse relaxation times, dominated by dipole–dipole interactions, are most effectively prolonged not only on-resonance but also for certain, generally large, resonance offsets. These correspond to a situation when, during the basic pulse separation, the frequency offset rotates the toggling-frame Hamiltonian by multiples of 180°. The implications of these results for the study of macroscopic translational diffusion using static-field-gradient NMR are discussed.
The Effectiveness of Urban Land Management of Addis Ababa City Administration: Case Study Yeka Sub-city
Creators: name: Solomon, Asmamaw
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2019

description: This study examined effectiveness of urban land management practices and challenges in Addis Ababa City Administration using Yeka Sub-City as a case study. The study design was descriptive case study. Data was collected from primary and secondary sources. Primary data was obtained through questionnaire from 138 selected respondents using simple random sampling technique, and through interviews from key respondents. The key respondentswere selected using non-probability purposive sampling technique. Secondary data involved reviewing relevant published and unpublished reports, procedural manuals and other relevant documents. Data collected through survey questionnaire was entered in to SPSS for statistical analysis, and data collected through interviews were analyzed using narrative description method. This study found that the existing land management and development office Yeka sub city are characterized by a lack of adequate capacity interms professional workers and advanced technologies and infra-structures. It also identified several challenges including, lack of complete inventory of land, , poor coordination among stakeholders, lack of aducate capacity interms workers and equipments, poor or un scientific land use plan, lack well organized land information,poor recording and controlling mechanisms of land resource,lack of clearly defined legal framework to control illegal settlement. The study recommends improving capacity of the land management; and clearly defining role, mandate, and coordination of offices involved in the land management process and scientifically designed land management system.
Convergence properties of Coherent State Path Integrals from Statistical Mechanics
Creators: name: Stolze, Joachim
Publisher: name: The American Institute of Physics
Year: 1987
Subjects: subject: 510

description: Coherent state path integral representations for matrix elements of density operators are compared to various formulations of coordinate space path integrals discussed recently [R. D. Coalson, J. Chem. Phys. 85, 926 (1986)]. The convergence properties of finite-dimensional approximations to these path integrals are tested for the harmonic oscillator. It is found that at low temperatures the coherent state path integrals converge much better than the coordinate space path integrals and thus should be preferred in numerical (e.g., Monte Carlo) calculations of low-temperature properties.
Determinants of the Effectiveness of the Distribution System: The Case of Repi-Wilmar Soap and Detergent SC
Creators: name: Bezie, Azmach
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2018

description: In today's business environment, the developing of effective distribution system becomes one of the major challenges in manufacturing firms. The general objective of this study is to investigate the effect of different factors that influence the effectiveness of distribution system in the case of Repi-Wilmar Soap and Detergent SC. The study has four main objectives: (1) to examine the effect of distribution strategy on the effectiveness of the distribution system of Repi-Wilmar, (2) to assess the influence of wholesaler motivation on the effectiveness of distribution system of Repi-Wilmar, (3) to analyze the influence of logistic capability on the effectiveness of the distribution system of Repi-Wilmar, (4) to identify the effect of government factors on the effectiveness of distribution system of Repi-Wilmar. This research has taken explanatory research design. The researcher used both primary and secondary data to get more relevant information. Data was collected from 355 respondents. Quantitative data was gathered through questionnaires and qualitative data was collected through observation and interviews due to this reason, the researcher used mixed research approach. Sample has been determined based on probability sampling and stratified sampling technique. The result findings indicated the distribution strategy, the logistic capability, the government's factor and the wholesaler motivation have positive and significant relations with the effectiveness of distribution system of the company. Based on the regression analysis, 39.6% of the variation of the output was explained by the distribution strategy, 28.4% of the variation of the output was explained by logistic capability, 13.0% of the variants of the output was explained by government factors and 11.0% of the variation of the output was explained by wholesaler motivation. Thus, the result revealed that 50.3% the variant of the effectiveness of distribution system has been responsible due to the influence of distribution strategy, logistic capability, government factors and wholesaler motivation. Therefore, study recommended that the company should give more attention about distribution strategy, logistic factor, government's factor and wholesaler motivation to enhance the effectiveness of distribution system of the company.
A note on interacting holographic dark energy with a Hubble-scale cutoff
Creators: name: Landim, Ricardo G.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Holographic dark energy with the Hubble radius as infrared cutoff has been considered as a candidate to explain the late-time cosmic acceleration and it can solve the coincidence problem. In this scenario, a non-zero equation of state is only possible if there is an interaction between dark energy and cold dark matter. In this paper, a set of phenomenological interactions is assumed and a detailed analysis of the possible values of the coupling constants is carried out, however the resulting matter power spectrum and cosmic microwave background temperature and polarization power spectra have a shape very far from the observed ones. These results rule out any value for the free parameters and it seems to indicate that the assumed interacting holographic dark energy with a Hubble-scale cutoff is not viable to explain the accelerated expansion of the Universe, when cosmological data are taken into account.
description: 8 pages, 4 figures. References added, typos corrected. Version accepted for publication in PRD
Engineering Bright Matter-Wave Solitons of Dipolar Condensates
Creators: name: Edmonds, M. J.
name: Bland, T.
name: Doran, R.
name: Parker, N. G.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We present a comprehensive analysis of the form and interaction of dipolar bright solitons across the full parameter space afforded by dipolar Bose-Einstein condensates, revealing the rich behaviour introduced by the non-local nonlinearity. Working within an effective one-dimensional description, we map out the existence of the soliton solutions and show three collisional regimes: free collisions, bound state formation and soliton fusion. Finally, we examine the solitons in their full three-dimensional form through a variational approach; along with regimes of instability to collapse and runaway expansion, we identify regimes of stability which are accessible to current experiments.
description: 10 pages, 5 figures
Eight : a studio investigation of the family
Creators: name: Peitsch, Flossie.
Publisher: name: Monash University
Year: 2022

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Experimental Demonstration of Quantum Pseudotelepathy
Creators: name: Xu, Jia-Min
name: Zhen, Yi-Zheng
name: Yang, Yu-Xiang
name: Cheng, Zi-Mo
name: Ren, Zhi-Cheng
name: Chen, Kai
name: Wang, Xi-Lin
name: Wang, Hui-Tian
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum pseudotelepathy is a strong form of nonlocality. Different from the conventional non-local games where quantum strategies win statistically, e.g., the Clauser-Horne-Shimony-Holt game, quantum pseudotelepathy in principle allows quantum players to with probability 1. In this work, we report a faithful experimental demonstration of quantum pseudotelepathy via playing the non-local version of Mermin-Peres magic square game, where Alice and Bob cooperatively fill in a 3 by 3 magic square. We adopt the hyperentanglement scheme and prepare photon pairs entangled in both the polarization and the orbital angular momentum degrees of freedom, such that the experiment is carried out in a resource-efficient manner. Under the locality and fair-sampling assumption, our results show that quantum players can simultaneously win all the queries over any classical strategy.
description: 6+5 pages; published version
Mapping dynamical systems with distributed time delays to sets of ordinary differential equations
Creators: name: Nevermann, Daniel Henrik
name: Gros, Claudius
Publisher: name: arXiv
Year: 2023
Subjects: subject: Dynamical Systems (math.DS)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: Real-world dynamical systems with retardation effects are described in general not by a single, precisely defined time delay, but by a range of delay times. An exact mapping onto a set of $N+1$ ordinary differential equations exists when the respective delay distribution is given in terms of a gamma distribution with discrete exponents. The number of auxiliary variables one needs to introduce, $N$, is inversely proportional to the variance of the delay distribution. The case of a single delay is therefore recovered when $N\to\infty$. Using this approach, denoted here the `kernel series framework', we examine systematically how the bifurcation phase diagram of the Mackey-Glass system changes under the influence of distributed delays. We find that local properties, f.i.\ the locus of a Hopf bifurcation, are robust against the introduction of broadened memory kernels. Period-doubling transitions and the onset of chaos, which involve non-local properties of the flow, are found in contrast to be more sensitive to distributed delays. In general, the observed effects are found to scale as $1/N$. Furthermore, we consider time-delayed systems exhibiting chaotic diffusion, which is present in particular for sinusoidal flows. We find that chaotic diffusion is substantially more pronounced for distributed delays. Our results indicate in consequence that modeling approaches of real-world processes should take the effects of distributed delay times into account.
description: 16 pages, 6 figures
Long-range entangled zero-mode state in a non-Hermitian lattice
Creators: name: Lin, S.
name: Zhang, X. Z.
name: Li, C.
name: Song, Z.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In contrast to a Hermitian system, in which zero modes are usually degenerate and localized edge state in the thermodynamic limit, the zero mode of a finite non-Hermitian system can be a single nontrivial long-range entangled state at the exceptional point (EP). In this work, we demonstrate this feature with a concrete example based on exact solutions. Numerical simulations show that the entangled state can be generated through the dynamic process with a high fidelity.
Dielectric relaxation in the fragile viscous liquid state of toluene
Creators: name: Böhmer, Roland
name: Döß, A.
name: Hinze, G.
name: Schiener, B.
name: Hemberger, J.
Publisher: name: American Institute of Physics
Year: 1997
Subjects: subject: 530

description: Dielectric measurements were carried out on viscous toluene covering a frequency range from 0.1 Hz to 1 MHz. In order to suppress the pronounced crystallization tendency of this supercooled liquid it was contained in thin walled capillaries with outer diameters of 300 µm. From the temperature dependence of the characteristic dielectric relaxation times it was found that toluene is one of the most fragile low molecular weight glass-forming liquids, with a fragility index m=105. By comparison with time constants available from other experimental techniques it appears that near the glass transition the dielectric relaxation mode is not the slowest one.
Orientational ordering of water molecules confined in beryl: A theoretical study
Creators: name: Klíč, Antonín
name: Janiš, Václav
name: Kadlec, Filip
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We present an improved model for studying the interactions between dipole moments of water molecules confined in beryl crystals, inspired by recent NMR experiments. Our model is based on a local crystal potential with dihexagonal symmetry for the rotations of water dipole moments, leading to deflection from the $ab$ hexagonal crystallographic plane. This potential shape has significant implications for dipole ordering, which is linked to the non-zero projection of the dipole moment on the hexagonal $c$ axis. To reveal the tendency toward equilibrium-ordered states, we used a variational mean-field approximation, Monte Carlo simulations, and quantum tunneling. Our analysis reveals three types of equilibrium-ordered states: a purely planar dipole order with an antiparallel arrangement in the adjacent planes, a configuration with deflected dipole moments ordered in antiparallel directions, and a helical structure of the dipoles twisting along the $c$ axis.
description: RevTeX4-2, 16 figures
CoAP-DoS: An IoT Network Intrusion Dataset
Creators: name: Mathews, Jared
name: Chatterjee, Prosenjit
name: Banik, Shankar
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cryptography and Security (cs.CR)
subject: Artificial Intelligence (cs.AI)
subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: The need for secure Internet of Things (IoT) devices is growing as IoT devices are becoming more integrated into vital networks. Many systems rely on these devices to remain available and provide reliable service. Denial of service attacks against IoT devices are a real threat due to the fact these low power devices are very susceptible to denial-of-service attacks. Machine learning enabled network intrusion detection systems are effective at identifying new threats, but they require a large amount of data to work well. There are many network traffic data sets but very few that focus on IoT network traffic. Within the IoT network data sets there is a lack of CoAP denial of service data. We propose a novel data set covering this gap. We develop a new data set by collecting network traffic from real CoAP denial of service attacks and compare the data on multiple different machine learning classifiers. We show that the data set is effective on many classifiers.
description: 6 pages, 8 figures, Publication Title: 2022 6th International Conference on Cryptography, Security and Privacy (CSP), eCF Paper Id: 1641864704381, accepted for publishing, not yet published
Determinants of Export Marketing Performance: The Case of Ethiopian Pulses, Oil Seeds and Spices Exporters
Creators: name: Alemayehu, Addis
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2019

description: Ethiopian pulses, oil seeds and spices export sector has been the second most important source of foreign currency to the country, after Coffee. However, the sector failed to achieve its contribution to the overall export performance of the country in the first GTP period. This study aims to shed light on the determinants of export marketing performance with special emphasis on Ethiopian firms engaged in exporting oil seeds, pulses and spices and members of an umbrella association, EPSOPEA. The factors studied using mixed research approach and studied variables include; Characteristics of export market, Characteristics of the export product, Presence and use of export marketing strategy, Firm/ Managerial characteristics and Institutional support-related factors. Consequently, only Institutional support-related factors were found to have significant effect on the dependent variable, Export marketing performance. Hence, it is revealed by the study that exporters are encouraged to engage in export business mainly due to; cheap loans and priority treatment they get from banks, high level government attention and recognition, and market promotion support from stakeholders like EPOSPEA & ECCSA and lastly NBE's lee way to exporters allowing them to use a portion of the foreign currency they earned from export business for other FOREX requiring (export related) businesses like imports, manufacturing and services. Further, exporters are found to be usually a price taker in their international dealings which in turn is impairing their position to be competitive in the international market. Hence, it is recommended that other monetary and fiscal policy measures be taken to encourage exporters to make them more competitive
Confirmation and refutation of very luminous galaxies in the early universe
Creators: name: Haro, Pablo Arrabal
name: Dickinson, Mark
name: Finkelstein, Steven L.
name: Kartaltepe, Jeyhan S.
name: Donnan, Callum T.
name: Burgarella, Denis
name: Carnall, Adam
name: Cullen, Fergus
name: Dunlop, James S.
name: Fernández, Vital
name: Fujimoto, Seiji
name: Jung, Intae
name: Krips, Melanie
name: Larson, Rebecca L.
name: Papovich, Casey
name: Pérez-González, Pablo G.
name: Amorín, Ricardo O.
name: Bagley, Micaela B.
name: Buat, Véronique
name: Casey, Caitlin M.
name: Chworowsky, Katherine
name: Cohen, Seth H.
name: Ferguson, Henry C.
name: Giavalisco, Mauro
name: Huertas-Company, Marc
name: Hutchison, Taylor A.
name: Kocevski, Dale D.
name: Koekemoer, Anton M.
name: Lucas, Ray A.
name: McLeod, Derek J.
name: McLure, Ross J.
name: Pirzkal, Norbert
name: Seillé, Lise-Marie
name: Trump, Jonathan R.
name: Weiner, Benjamin J.
name: Wilkins, Stephen M.
name: Zavala, Jorge A.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: During the first 500 million years of cosmic history, the first stars and galaxies formed, seeding the Universe with heavy elements and eventually reionizing the intergalactic medium. Observations with JWST have uncovered a surprisingly high abundance of candidates for early star-forming galaxies, with distances (redshifts, $z$), estimated from multi-band photometry, as large as $z\approx 16$, far beyond pre-JWST limits. While generally robust, such photometric redshifts can suffer from degeneracies and occasionally catastrophic errors. Spectroscopic measurement is required to validate these sources and to reliably quantify physical properties that can constrain galaxy formation models and cosmology. Here we present JWST spectroscopy that confirms redshifts for two very luminous galaxies with $z > 11$, but also demonstrates that another candidate with suggested $z\approx 16$ instead has $z = 4.9$, with an unusual combination of nebular line emission and dust reddening that mimics the colors expected for much more distant objects. These results reinforce evidence for the early, rapid formation of remarkably luminous galaxies, while also highlighting the necessity of spectroscopic verification. The large abundance of bright, early galaxies may indicate shortcomings in current galaxy formation models, or deviation from physical properties (such as the stellar initial mass function) that are generally believed to hold at later times.
description: Accelerated Article Preview (AAP) version published in Nature
Einstein-Podolsky-Rosen paradox in a hybrid bipartite system
Creators: name: Dąbrowski, Michał
name: Parniak, Michał
name: Wasilewski, Wojciech
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Atomic Physics (physics.atom-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Entanglement of light and matter is an essential resource for effective quantum engineering. In particular, collective states of atomic ensembles are robust against decoherence while preserving the possibility of strong interaction with quantum states of light. While previous approaches to continous-variable quantum interfaces relied on quadratures of light, here we present an approach based on spatial structure of light-atom entanglement. We create and characterize a 12-dimensional entangled state exhibiting quantum correlations between a photon and an atomic ensemble in position and momentum bases. This state allows us to demonstrate the original Einstein-Podolsky-Rosen (EPR) paradox with two different entities, with an unprecedented delay time of 6 $μ$s between generation of entanglement and detection of the atomic state.
description: 4 pages, 3 figures, 1 table, supplement available at https://doi.org/10.1364/OPTICA.4.000272
Topological Theory of Phase Transitions
Creators: name: Gori, Matteo
name: Franzosi, Roberto
name: Pettini, Giulio
name: Pettini, Marco
Publisher: name: arXiv
Year: 2022
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mathematical Physics (math-ph)
subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: The investigation of the Hamiltonian dynamical counterpart of phase transitions, combined with the Riemannian geometrization of Hamiltonian dynamics, has led to a preliminary formulation of a differential-topological theory of phase transitions. In fact, in correspondence of a phase transition there are peculiar geometrical changes of the mechanical manifolds that are found to stem from changes of their topology. These findings, together with two theorems, have suggested that a topological theory of phase transitions can be formulated to go beyond the limits of the existing theories. Among other advantages, the new theory applies to phase transitions in small $N$ systems (that is, at nanoscopic and mesoscopic scales), and in the absence of symmetry-breaking. However, the preliminary version of the theory was incomplete and still falsifiable by counterexamples. The present work provides a relevant leap forward leading to an accomplished development of the topological theory of phase transitions paving the way to further developments and applications of the theory that can be no longer hampered.
description: 44 pages, 13 figures, J. Phys. A: Math. Theor. in press
The mass-ratio and eccentricity distributions of barium and S stars, and red giants in open clusters
Creators: name: Van der Swaelmen, Mathieu
name: Boffin, Henri M. J.
name: Jorissen, Alain
name: Van Eck, Sophie
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: In order to identify diagnostics distinguishing between pre- and post-mass-transfer systems, the mass-ratio distribution and period - eccentricity (P - e) diagram of barium and S stars are compared to those of the sample of binary red giants in open clusters from Mermilliod et al. (2007). From the analysis of the mass-ratio distribution for the cluster binary giants, we find an excess of systems with companion masses between 0.58 and 0.87 Msun, typical for white dwarfs. They represent 22% of the sample, which are thus candidate post-mass-transfer systems. Among these candidates which occupy the same locus as the barium and S stars in the (P-e) diagram, only 33% (= 4/12) show a chemical signature of mass transfer in the form of s-process overabundances (from rather moderate -- about 0.3 dex -- to more extreme -- about 1 dex). These s-process-enriched cluster stars show a clear tendency to be in the clusters with the lowest metallicity in the sample, confirming the classical prediction that the s-process nucleosynthesis is more efficient at low metallicities (the only strong barium star in our sample is found in the cluster with the lowest metallicity, i.e., star 173 in NGC 2420, with [Fe/H] = -0.26). The s-process overabundance is not clearly correlated with the cluster turnoff (TO) mass (such a correlation would instead hint at the importance of the dilution factor). We find as well a mild barium star in NGC 2335, a cluster with a large TO mass of 4.3 Msun, which implies that intermediate-mass AGB stars still operate the s-process and the third dredge-up.
description: Accepted in Astronomy & Astrophysics; v.2 (language-edited)
Strong chiral optical force for small chiral molecules based on electric-dipole interactions, inspired by the asymmetrical hydrozoan $\textit{Velella velella}$
Creators: name: Cameron, Robert P.
name: McArthur, Duncan
name: Yao, Alison M.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Optics (physics.optics)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Drawing inspiration from a remarkable chiral force found in nature, we show that a static electric field combined with an optical lin$\perp$lin polarization standing wave can exert a chiral optical force on a small chiral molecule that is several orders of magnitude stronger than other chiral optical forces proposed to date, being based on leading electric-dipole interactions rather than relying on weak magnetic-dipole and electric-quadrupole interactions. Our chiral optical force applies to most small chiral molecules, including isotopically chiral molecules, and does not require a specific energy-level structure. Potential applications range from chiral molecular matter-wave interferometry for precision metrology and tests of fundamental physics to the resolution of enantiomers for use in chemistry and biology.
Rate-splitting multiple access for non-terrestrial communication and sensing networks
Creators: name: Yin, Longfei
Publisher: name: Imperial College London
Year: 2023

description: Rate-splitting multiple access (RSMA) has emerged as a powerful and flexible non-orthogonal transmission, multiple access (MA) and interference management scheme for future wireless networks. This thesis is concerned with the application of RSMA to non-terrestrial communication and sensing networks. Various scenarios and algorithms are presented and evaluated. First, we investigate a novel multigroup/multibeam multicast beamforming strategy based on RSMA in both terrestrial multigroup multicast and multibeam satellite systems with imperfect channel state information at the transmitter (CSIT). The max-min fairness (MMF)-degree of freedom (DoF) of RSMA is derived and shown to provide gains compared with the conventional strategy. The MMF beamforming optimization problem is formulated and solved using the weighted minimum mean square error (WMMSE) algorithm. Physical layer design and link-level simulations are also investigated. RSMA is demonstrated to be very promising for multigroup multicast and multibeam satellite systems taking into account CSIT uncertainty and practical challenges in multibeam satellite systems. Next, we extend the scope of research from multibeam satellite systems to satellite- terrestrial integrated networks (STINs). Two RSMA-based STIN schemes are investigated, namely the coordinated scheme relying on CSI sharing and the co- operative scheme relying on CSI and data sharing. Joint beamforming algorithms are proposed based on the successive convex approximation (SCA) approach to optimize the beamforming to achieve MMF amongst all users. The effectiveness and robustness of the proposed RSMA schemes for STINs are demonstrated. Finally, we consider RSMA for a multi-antenna integrated sensing and communications (ISAC) system, which simultaneously serves multiple communication users and estimates the parameters of a moving target. Simulation results demonstrate that RSMA is beneficial to both terrestrial and multibeam satellite ISAC systems by evaluating the trade-off between communication MMF rate and sensing Cramer-Rao bound (CRB).
Optimal control of topological quantum systems
Creators: name: Raii, Said Omar
Publisher: name: Imperial College London
Year: 2023

description: Topological quantum computation provides an architecture for encoding quantum information in such a way as to be theoretically robust to local noise. Logical qubits are encoded in topological degrees of freedom typically in spin-lattice models. Excitations in the spin-lattice models manifest as anyons, generalisations of bosons and fermions that exist in two dimensions. Proposals for experimental realisation of these topological systems have previously relied on perfect anyon creation in a time independent-manner or in the case of time-dependent proposals have primarily relied on adiabatic, therefore slow, dynamics. The aim of this thesis is to use quantum control to create anyons and encode logical qubits in topological systems without the requirement for adiabaticity and long timescales. First, we demonstrate the creation of abelian anyons using time-dependent controls in the toric code model, a system that is useful as a quantum memory. We show that this may be done within arbitrarily short timescales at the expense of larger magnitude control pulses. Additionally, we investigate the robustness of our protocol in the face of theoretical errors in anyon creation. Secondly, we investigate the creation of non-abelian anyons in the Kitaev honeycomb model. By fermionising a time-dependent version of the model we demonstrate how optimal control theory can allow for anyon creation in faster-than-adiabatic time. Moreover, we show that the particular method we develop to achieve this scales only linearly in the number of spins in the lattice. Thirdly, we investigate defect creation in the surface code, a generalisation of the toric code that does not require periodic boundary conditions. Optimal quantum control is used to show how defects may be created faster than with the typical adiabatic procedures. Additionally, a method using mapping of dynamical Lie algebras is used to demonstrate that optimal control techniques may be extended to operations whose dynamics require solving in a large Hilbert space.
Static and dynamical magnetic properties of the extended Kitaev-Heisenberg model with spin vacancies
Creators: name: Li, Shaozhi
name: Fishman, Randy S.
name: Berlijn, Tom
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences
subject: 65P10

description: Motivated by the potential to suppress the antiferromagnetic long-range order in favor of the long-sought-after Kitaev quantum spin liquid state, we study the effect of spin vacancies in the extended Kitaev-Heisenberg model. In particular, we focus on a realistic model obtained from fitting inelastic neutron scattering on $α$-RuCl$_3$. We observe that the long-range zigzag magnetic ordered state only survives when the doping concentration is smaller than 5\%. Upon further increasing the spin vacancy concentration, the ground state becomes a short-range ordered state at low temperatures. Compared with experiments, our classical solution over-stabilizes the zigzag correlation in the presence of spin vacancies. Our theoretical results provide guidance toward interpreting inelastic neutron scattering experiments on magnetically diluted Kitaev candidate materials.
description: 9 figures
Charge Migration in Heterocyclic Five-Membered Rings
Creators: name: Giri, Sucharita
name: Dixit, Gopal
name: Tremblay, Jean Christophe
Publisher: name: arXiv
Year: 2023
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: This contribution presents numerical simulations of N-electron dynamics in heterocyclic five-membered ring molecules to shed light on the effect of molecular symmetry on charge migration. Laser-driven dynamics is studied using the hybrid time-dependent density functional theory/configuration methodology, and the ensuing field-free charge migration is investigated by means of transient electronic flux density maps. Our results demonstrate that the charge migration in aromatic rings is sensitive to the presence of heteroatoms such as oxygen and nitrogen. Their presence within the ring induces significant modifications of the character in the ground and low-lying electronic states, which is imprinted in the charge migration mechanism.
Learnability Enhancement for Low-light Raw Denoising: Where Paired Real Data Meets Noise Modeling
Creators: name: Feng, Hansen
name: Wang, Lizhi
name: Wang, Yuzhi
name: Huang, Hua
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Image and Video Processing (eess.IV)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Low-light raw denoising is an important and valuable task in computational photography where learning-based methods trained with paired real data are mainstream. However, the limited data volume and complicated noise distribution have constituted a learnability bottleneck for paired real data, which limits the denoising performance of learning-based methods. To address this issue, we present a learnability enhancement strategy to reform paired real data according to noise modeling. Our strategy consists of two efficient techniques: shot noise augmentation (SNA) and dark shading correction (DSC). Through noise model decoupling, SNA improves the precision of data mapping by increasing the data volume and DSC reduces the complexity of data mapping by reducing the noise complexity. Extensive results on the public datasets and real imaging scenarios collectively demonstrate the state-of-the-art performance of our method. Our code is available at: https://github.com/megvii-research/PMN.
description: 9 pages, 8 figures, to be published in ACMMM 2022
Error estimates with explicit constants for the Sinc approximation over infinite intervals
Creators: name: Okayama, Tomoaki
Publisher: name: arXiv
Year: 2016
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 65D05, 65D15, 65G99

description: The Sinc approximation is a function approximation formula that attains exponential convergence for rapidly decaying functions defined on the whole real axis. Even for other functions, the Sinc approximation works accurately when combined with a proper variable transformation. The convergence rate has been analyzed for typical cases including finite, semi-infinite, and infinite intervals. Recently, for verified numerical computations, a more explicit, "computable" error bound has been given in the case of a finite interval. In this paper, such explicit error bounds are derived for other cases.
description: Keywords: Sinc approximation, conformal map, double-exponential transformation, infinite interval, error bound
The Impact Of Service Quality On The Satisfaction Of Foreign Customers In The Case Of Commercial Bank Of Ethiopia
Creators: name: Fikre, Fetene
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2017

description: The general objective of this study is to assess the impact of service quality on the satisfaction of foreign customers in CBE. The focus of the study was on the three branches of commercial Bank of Ethiopia (Africa Union, ECA and IBD branches). To achieve the objectives of this study, data was collected through questionnaire from a sample of 308 foreign customers. Convenient sampling technique was employed in the study with Statistical Package for Social Scientist (SPSS) version 20.00 used in the analysis. The data collected from the questionnaire were analyzed using Statistical tools such as mean, standard deviation, correlation, and multiple regression analysis.The perceptions of foreign customers of commercial bank of Ethiopia were assessed under the five dimensions of service quality through SERVPERF method. The results of this study indicate that, all the five service quality dimensions (tangibility, reliability, responsiveness, assurance and empathy) have positive and significant relationship with foreign customers' satisfaction. The finding of this study also indicates that foreign customers were most satisfied with the responsiveness dimensions of service quality. On the contrary, foreigners were less satisfied with reliability and tangibility dimensions of service quality.Furthermore, the service quality dimensions (tangibility, reliability, assurance, responsiveness and empathy) significantly explain 80% of the variations in the satisfaction of foreign customers.The outcome of study will enhance the Bank stakeholders to identify and assess the significance of service quality dimensions and then to take an action to fix it. In general, to ensure the satisfaction of foreign customers, commercial bank of Ethiopia has to asses regularly the process of service delivery
Scalar Love numbers and Love symmetries of 5-dimensional Myers-Perry black holes
Creators: name: Charalambous, Panagiotis
name: Ivanov, Mikhail M.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The near-zone ``Love'' symmetry resolves the naturalness issue of black hole Love number vanishing with $\text{SL}\left(2,\mathbb{R}\right)$ representation theory. Here, we generalize this proposal to $5$-dimensional asymptotically flat and doubly spinning (Myers-Perry) black holes. We consider the scalar response of Myers-Perry black holes and extract its static scalar Love numbers. In agreement with the naturalness arguments, these Love numbers are, in general, non-zero and exhibit logarithmic running unless certain resonant conditions are met; these conditions include new cases with no previously known analogs. We show that there exist two near-zone truncations of the equations of motion that exhibit enhanced $\text{SL}\left(2,\mathbb{R}\right)$ Love symmetries that explain the vanishing of the static scalar Love numbers in the resonant cases. These Love symmetries can be interpreted as local $\text{SL}\left(2,\mathbb{R}\right)\times\text{SL}\left(2,\mathbb{R}\right)$ near-zone symmetries spontaneously broken down to global $\text{SL}\left(2,\mathbb{R}\right)\times U\left(1\right)$ symmetries by the periodic identification of the azimuthal angles. We also discover an infinite-dimensional extension of the Love symmetry into $\text{SL}\left(2,\mathbb{R}\right)\ltimes\hat{U}\left(1\right)_{\mathcal{V}}^2$ that contains both Love symmetries as particular subalgebras, along with a family of $\text{SL}\left(2,\mathbb{R}\right)$ subalgebras that reduce to the exact near-horizon Myers-Perry black hole isometries in the extremal limit. Finally, we show that the Love symmetries acquire a geometric interpretation as isometries of subtracted (effective) black hole geometries that preserve the internal structure of the black hole and interpret these non-extremal $\text{SL}\left(2,\mathbb{R}\right)$ structures as remnants of the enhanced isometry of the near-horizon extremal geometries.
description: 45+16 pages, 3 Figures