cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Spin-Mechanical Scheme with Color Centers in Hexagonal Boron Nitride Membranes
Creators: name: Abdi, Mehdi
name: Hwang, Myung-Joong
name: Aghtar, Mortaza
name: Plenio, Martin B.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Recently observed quantum emitters in hexagonal boron nitride (hBN) membranes have a potential for achieving high accessibility and controllability thanks to the lower spatial dimension. Moreover, these objects naturally have a high sensitivity to vibrations of the hosting membrane due to its low mass density and high elasticity modulus. Here, we propose and analyze a spin-mechanical system based on color centers in a suspended hBN mechanical resonator. Through group theoretical analyses and ab-initio calculation of the electronic and spin properties of such a system, we identify a spin doublet ground state and demonstrate that a spin-motion interaction can be engineered which enables ground state cooling of the mechanical resonator. We also present a toolbox for initialization, rotation, and readout of the defect spin qubit. As a result the proposed setup presents the possibility for studying a wide range of physics. To illustrate its assets, we show that a fast and noise resilient preparation of a multicomponent cat state and a squeezed state of the mechanical resonator is possible; the latter is achieved by realizing the extremely detuned, ultrastrong coupling regime of the Rabi model, where a phonon superradiant phase transition is expected to occur.
description: Published version
$1/f^α$ power spectrum in the Kardar-Parisi-Zhang universality class
Creators: name: Takeuchi, Kazumasa A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Probability (math.PR)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: The power spectrum of interface fluctuations in the $(1+1)$-dimensional Kardar-Parisi-Zhang (KPZ) universality class is studied both experimentally and numerically. The $1/f^α$-type spectrum is found and characterized through a set of "critical exponents" for the power spectrum. The recently formulated "aging Wiener-Khinchin theorem" accounts for the observed exponents. Interestingly, the $1/f^α$ spectrum in the KPZ class turns out to contain information on a universal distribution function characterizing the asymptotic state of the KPZ interfaces, namely the Baik-Rains universal variance. It is indeed observed in the presented data, both experimental and numerical, and for both circular and flat interfaces, in the long time limit.
description: 19 pages, 7 figures
Partitioning a macroscopic system into independent subsystems
Creators: name: Site, Luigi Delle
name: Ciccotti, Giovanni
name: Hartmann, Carsten
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 37M25, 82B05, 82B24, 94A17

description: We discuss the problem of partitioning a macroscopic system into a collection of independent subsystems. The partitioning of a system into replica-like subsystems is nowadays a subject of major interest in several field of theoretical and applied physics, and the thermodynamic approach currently favoured by practitioners is based on a phenomenological definition of an interface energy associated with the partition, due to a lack of easily computable expressions for a microscopic (i.e.~particle-based) interface energy. In this article, we outline a general approach to derive sharp and computable bounds for the interface free energy in terms of microscopic statistical quantities. We discuss potential applications in nanothermodynamics and outline possible future directions.
description: This is an author-created, un-copyedited version of an article accepted for publication in JSTAT
A nearest-neighbour discretisation of the regularized stokeslet boundary integral equation
Creators: name: Smith, David J.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences
subject: 76D07, 76M15, 76Z99

description: The method of regularized stokeslets is extensively used in biological fluid dynamics due to its conceptual simplicity and meshlessness. This simplicity carries a degree of cost in computational expense and accuracy because the number of degrees of freedom used to discretise the unknown surface traction is generally significantly higher than that required by boundary element methods. We describe a meshless method based on nearest-neighbour interpolation that significantly reduces the number of degrees of freedom required to discretise the unknown traction, increasing the range of problems that can practically solved, without excessively complicating the task of the modeller. The nearest-neighbour technique is tested against the classical problem of rigid body motion of a sphere immersed in very viscous fluid, then applied to the more complex biophysical problem of calculating the diffusion timescales of a macromolecular structure modelled by three closely-spaced non-slender rods. A heuristic for finding the required density of force and quadrature points by numerical refinement is suggested. Matlab/GNU Octave code for the key steps of the algorithm are given, which predominantly use basic linear algebra operations, with a full implementation being provided on github. Compared with the standard Nyström discretisation more accurate and substantially more efficient results can be obtained by de-refining the force discretisation relative to the quadrature discretisation: a cost reduction of over 10 times with improved accuracy is observed. This improvement comes at minimal additional technical complexity. Future avenues to develop the algorithm are then discussed.
description: 22 pages, 2 figures, accepted in Journal of Computational Physics
Precision measurement and interpretation of inclusive $W^+$, $W^-$ and $Z/γ^*$ production cross sections with the ATLAS detector
Creators: name: ATLAS Collaboration
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: High-precision measurements by the ATLAS Collaboration are presented of inclusive $W^+\to\ell^+ν$, $W^-\to\ell^-\barν$ and $Z/γ^*\to\ell\ell$ ($\ell=e,μ$) Drell-Yan production cross sections at the LHC. The data were collected in proton-proton collisions at $\sqrt{s} = 7$ TeV with an integrated luminosity of 4.6 fb$^{-1}$. Differential $W^+$ and $W^-$ cross sections are measured in a lepton pseudorapidity range $|η_{\ell}| = 2.5$. Differential $Z/γ^*$ cross sections are measured as a function of the absolute dilepton rapidity, for $|y_{\ell\ell}| < 3.6$, for three intervals of dilepton mass, $m_{\ell\ell}$, extending from 46 to 150 GeV. The integrated and differential electron- and muon-channel cross sections are combined and compared to theoretical predictions using recent sets of parton distribution functions. The data, together with the final inclusive $e^{\pm}p$ scattering cross-section data from H1 and ZEUS, are interpreted in a next-to-next-to-leading-order QCD analysis, and a new set of parton distribution functions, ATLAS-epWZ16, is obtained. The ratio of strange-to-light sea-quark densities in the proton is determined more accurately than in previous determinations based on collider data only, and is established to be close to unity in the sensitivity range of the data. A new measurement of the CKM matrix element $|V_{cs}|$ is also provided.
description: 98 pages in total, author list starting page 82, 32 figures, 29 tables, published in EPJC, All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2012-20
On non-homogeneous tachyon condensation in closed string theory
Creators: name: Giribet, Gaston
name: Rado, Laura
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Lorentzian continuation of the Sine-Liouville model describes non-homogeneous rolling closed string tachyon. Via T-duality, this relates to the gauged $H_+^3$ Wess-Zumino-Witten model at subcritical level. This model is exactly solvable. We give a closed formula for the 3-point correlation functions for the model at level k within the range 02 in a similar way as how the Harlow-Maltz-Witten 3-point function of timelike Liouville field theory relates to the analytic continuation of the Dorn-Otto-Zamolodchikov-Zamolodchikov structure constants: We find that the ratio between both 3-point functions can be written in terms of the Jacobi's $θ$-function, while their product exhibits remarkable cancellations and eventually factorizes. Our formula is consistent with previous proposals made in the literature.
description: 26 pages. V2 discussion extended. Version to appear in JHEP
Loop Vertex Expansion for Higher Order Interactions
Creators: name: Rivasseau, Vincent
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: This note provides an extension of the constructive loop vertex expansion to stable interactions of arbitrarily high order, opening the way to many applications. We treat in detail the example of the $(\bar ϕϕ)^p$ field theory in zero dimension. We find that the important feature to extend the loop vertex expansion is not to use an intermediate field representation, but rather to force integration of exactly one particular field per vertex of the initial action.
description: 16 pages, 2 figures, V2, minor modifications
title: The search for trace elements in stardust silicate grains
Creators: name: Leitner, Jan
name: Hoppe, Peter
name: Trieloff, Mario
Publisher: name: Deutsche Geologische Gesellschaft - Geologische Vereinigung e.V. (DGGV)
Year: 2022

description:
Isotopically anomalous dust grains that formed in the outflows of evolved stars and in the ejecta of stellar explosions are a minor, but important component of primitive Solar System materials. These grains carry records of stellar nucleosynthesis and evolution, circumstellar grain formation, and stars contributing material to the nascent Solar System. Silicates are the most abundant type of presolar dust available for single grain analyses [1]. Presolar SiC and graphite contain various amounts of trace elements [e.g., 2], while for O-rich grains, only one study reported Sr in an O-rich grain [3]. Here, we report on a search for trace elements in a large presolar silicate by NanoSIMS. Measurements were performed with the Hyperion RF plasma O-source using three different mass sequences. Strontium, Zirconium, and Cerium were identified, with Sr/Si in compliance with astrophysical models. Zr/Si and Ce/Si ratios exceed model predictions, indicating additional effects governing their incorporation. The 90Zr- and 140Ce-distributions are correlated with 48Ti. For a gas of solar composition, Sr and Ce would condense into titanate, while Zr forms ZrO2 at higher temperatures. Due to chemical similarities between Zr and Ti, ZrO2 might have been incorporated into Sr- and Ce-bearing Ti-oxides, serving as condensation nuclei for the silicate [4].

References: [1] Floss C. & Haenecour P. (2016) Geochemical Journal 50: 3–25. [2] Amari S. et al. (1995) Meteoritics 30:679–693. [3] Leitner J. et al. (2018) Geochimica et Cosmochimica Acta 221:255–274. [4] Gail H.-P. & Sedlmayr E. (1998) Faraday Discussions 109:303–319.
Direct Comparison of Fractional and Integer Quantized Hall Resistance
Creators: name: Ahlers, Franz J.
name: Götz, Martin
name: Pierz, Klaus
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We present precision measurements of the fractional quantized Hall effect where the quantized resistance $R^{[1/3]}$ in the fractional quantum Hall state at filling factor 1/3 was compared with a quantized resistance $R^{[2]}$, represented by an integer quantum Hall state at filling factor 2. A cryogenic current comparator bridge capable of currents down to the nanoampere range was used to directly compare two resistance values of two GaAs-based devices located in two cryostats. A value of $1 - (5.3 \pm 6.3) 10^{-8}$ (95% confidence level) was obtained for the ratio $(R^{[1/3]}/6R^{[2]})$. This constitutes the most precise comparison of integer resistance quantization (in terms of $h/e^2$) in single-particle systems and of fractional quantization in fractionally charged quasi-particle systems. While not relevant for practical metrology, such a test of the validity of the underlying physics is of significance in the context of the up-coming revision of the SI.
Analysis of Agent Expertise in Ms. Pac-Man using Value-of-Information-based Policies
Creators: name: Sledge, Isaac J.
name: Principe, Jose C.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: Conventional reinforcement learning methods for Markov decision processes rely on weakly-guided, stochastic searches to drive the learning process. It can therefore be difficult to predict what agent behaviors might emerge. In this paper, we consider an information-theoretic cost function for performing constrained stochastic searches that promote the formation of risk-averse to risk-favoring behaviors. This cost function is the value of information, which provides the optimal trade-off between the expected return of a policy and the policy's complexity; policy complexity is measured by number of bits and controlled by a single hyperparameter on the cost function. As the policy complexity is reduced, the agents will increasingly eschew risky actions. This reduces the potential for high accrued rewards. As the policy complexity increases, the agents will take actions, regardless of the risk, that can raise the long-term rewards. The obtainable reward depends on a single, tunable hyperparameter that regulates the degree of policy complexity. We evaluate the performance of value-of-information-based policies on a stochastic version of Ms. Pac-Man. A major component of this paper is the demonstration that ranges of policy complexity values yield different game-play styles and explaining why this occurs. We also show that our reinforcement-learning search mechanism is more efficient than the others we utilize. This result implies that the value of information theory is appropriate for framing the exploitation-exploration trade-off in reinforcement learning.
description: IEEE Transactions on Computational Intelligence and Artificial Intelligence in Games
Quantum Paramagnet and Frustrated Quantum Criticality in a Spin-One Diamond Lattice Antiferromagnet
Creators: name: Chen, Gang
Publisher: name: arXiv
Year: 2017
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Motivated by the proposal of topological quantum paramagnet in the diamond lattice antiferromagnet NiRh$_2$O$_4$, we propose a minimal model to describe the magnetic interaction and properties of the diamond material with the spin-one local moments. Our model includes the first and second neighbor Heisenberg interactions as well as a local single-ion spin anisotropy that is allowed by the spin-one nature of the local moment and the tetragonal symmetry of the system. We point out that there exists a quantum phase transition from a trivial quantum paramagnet when the single-ion spin anisotropy is dominant to the magnetic ordered states when the exchange is dominant. Due to the frustrated spin interaction, the magnetic excitation in the quantum paramagnetic state supports extensively degenerate band minima in the spectra. As the system approaches the transition, extensively degenerate bosonic modes become critical at the criticality, giving rise to unusual magnetic properties. Our phase diagram and experimental predictions for different phases provide a guildeline for the identification of the ground state for NiRh$_2$O$_4$. Although our results are fundamentally different from the proposal of topological quantum paramagnet, it represents interesting possibilities for spin-one diamond lattice antiferromagnets.
description: 6+3 pages, 5 figures. published version
Do non-relativistic neutrinos oscillate?
Creators: name: Akhmedov, Evgeny
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We study the question of whether oscillations between non-relativistic neutrinos or between relativistic and non-relativistic neutrinos are possible. The issues of neutrino production and propagation coherence and their impact on the above question are discussed in detail. It is demonstrated that no neutrino oscillations can occur when neutrinos that are non-relativistic in the laboratory frame are involved, except in a strongly mass-degenerate case. We also discuss how this analysis depends on the choice of the Lorentz frame. Our results are for the most part in agreement with Hinchliffe's rule.
description: LaTeX, 22 pages. V2: typos corrected; minor textual changes. V3: sec. 3 rewritten; appendix on wave packet spreading added; small changes in sec. 2. Results and conclusions unchanged
QKZ-Ruijsenaars correspondence revisited
Creators: name: Zabrodin, A.
name: Zotov, A.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mathematical Physics (math-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Physical sciences

description: We discuss the Matsuo-Cherednik type correspondence between the quantum Knizhnik-Zamolodchikov equations associated with $GL(N)$ and the $n$-particle quantum Ruijsenaars model, with $n$ being not necessarily equal to $N$. The quasiclassical limit of this construction yields the quantum-classical correspondence between the quantum spin chains and the classical Ruijsenaars models.
description: 14 pages, minor corrections
On a base change conjecture for higher zero-cycles
Creators: name: Lüders, Morten
Publisher: name: arXiv
Year: 2016
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics

description: We show the surjectivity of a specialisation map on higher $(0,1)$-cycles for a smooth projective scheme over an excellent henselian discrete valuation ring. This gives evidence for a conjecture stated in an article of Kerz, Esnault and Wittenberg saying that base change holds for such schemes in general for motivic cohomology in degrees $(i,d)$ for fixed $d$ being the relative dimension over the base. Furthermore, the specialisation map we study is related to a finiteness conjecture for the $n$-torsion of $CH_0(X)$, where $X$ is a variety over a $p$-adic field.
description: 10 pages, final version
Investigation of 1,3,4-Oxadiazol-2(3H)-ones as Heterocyclic, Amidoisocyanate Precursors
Creators: name: Gagné Monfette, William
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 2023
Subjects: amido-isocyanates
hydrazides
aza-peptides
Hydantoin
isocyanates
masked isocyanates

description: Isocyanate chemistry is well-known and has been studied and exploited for years. N-Isocyanate derivatives, however, are scarce and far less understood. These are divided in three subclasses: the aminoisocyanates, the iminoisocyanates, and the rarest of them all, the amido-isocyanates. The latter are underdeveloped and understudied. Herein, studies that resulted in evidence for the existence of N_β-amido–isocyanates, and validated their use in a masked isocyanate strategy, will be described. Suitable precursors, N_β-acyl phenylcarbazide derivatives (activated aza-dipeptides), were synthesized in the context of aza-tripeptide synthesis. The 1,3,4-oxadiazol-2(3H)-one intermediate was formed quickly in the course of the reaction, and an equilibrium between the free N_β-amido-isocyanate and the 1,3,4-oxadiazol-2(3H)-ones was established. Longer reaction times, in presence of amino amide nucleophiles, led to the formation of hydantoins or aza-tripeptides with full consumption of both the starting material and the oxadiazolone intermediate, yielded 14 hydantoins and 4 aza-tripeptides in 51-79% isolated yields. Experiments were performed to support the formation of an amido-isocyanate intermediate and discriminate between pathways possibly involving the formation of a tetrahedral oxyanionic intermediate versus the trapping of an N-isocyanate by a nucleophile. A control reaction in which the N_α in the starting material was methylated completely suppressed the formation of the isocyanate intermediate and shut down the reaction, lending supporting the isocyanate formation pathway. The hydrogen at this position is crucial for the formation of the isocyanate, which can be deprotonated and form a neutral isocyanate species. To further support the mechanistic hypothesis, established C-isocyanate chemistry, in which isocyanates react with carboxylates to form amides, was applied to a series of oxadiazolones. This transformation cannot occur in the absence of an isocyanate. This reaction yielded 8 different N_β-acyl hydrazides with moderate to good yields, again supporting the formation of the rare amido-isocyanates. Overall, this work supports the formation of amido-isocyanates in equilibrium with their corresponding 1,3,4-oxadiazol-2(3H)-ones and validated that the latter are masked amido-isocyanates, species that have been rarely studied in the literature.
Negative electronic compressibility enables electrically-induced charge density waves in a two-dimensional electron liquid
Creators: name: Hroblak, Erica E.
name: Principi, Alessandro
name: Zhao, Hui
name: Vignale, Giovanni
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We show that the negative electronic compressibility of two-dimensional electronic systems at sufficiently low density enables the generation of charge density waves through the application of a uniform force field, provided no current is allowed to flow. The wavelength of the density oscillations is controlled by the magnitude of the (negative) screening length, and their amplitude is proportional to the applied force. Both are electrically tunable.
description: 4 pages, 5 figures
Casimir energy for acoustic phonons in graphene
Creators: name: Koohsarian, Y.
name: Javidan, K.
name: Shirzad, A.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We find the Casimir energy, at finite temperature, for acoustic phonons in a Graphene sheet suspended over a rectangular trench, and the corresponding Casimir forces are interpreted as correction terms to the built-in tensions of the Graphene. We show that these corrections generally break the tensional isotropy of the membrane, and can increase or decrease the membrane tension. We demonstrate that for a narrow rectangular trench with side-lengths in the order of few nanometers and few micrometers, these temperature corrections are expected to be noticeable ($\sim 10^{-4} N/m$) at the room temperature. These corrections would be even more considerable by increasing the temperature, and can be applied for adjusting the built-in tension of the Graphene. Consequently we introduce a corrected version for the fundamental resonance frequency of the Graphene resonator.
description: 11pages, one figure
Hamiltonian Formulation of the Conservative Self-Force Dynamics in the Kerr Geometry
Creators: name: Fujita, Ryuichi
name: Isoyama, Soichiro
name: Tiec, Alexandre Le
name: Nakano, Hiroyuki
name: Sago, Norichika
name: Tanaka, Takahiro
Publisher: name: arXiv
Year: 2016
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We formulate a Hamiltonian description of the orbital motion of a point particle in Kerr spacetime for generic (eccentric, inclined) orbits, which accounts for the effects of the conservative part of the gravitational self-force. This formulation relies on a description of the particle's motion as geodesic in a certain smooth effective spacetime, in terms of (generalized) action-angle variables. Clarifying the role played by the gauge freedom in the Hamiltonian dynamics, we extract the gauge-invariant information contained in the conservative self-force. We also propose a possible gauge choice for which the orbital dynamics can be described by an effective Hamiltonian, written solely in terms of the action variables. As an application of our Hamiltonian formulation in this gauge, we derive the conservative self-force correction to the orbital frequencies of Kerr innermost stable spherical (inclined or circular) orbits. This gauge choice also allows us to establish a "first law of mechanics" for black-hole-particle binary systems, at leading order beyond the test-mass approximation.
description: 55 pages, 0 figures, matches the published version
$0$-$π$ transitions in a Josephson junction of irradiated Weyl semimetal
Creators: name: Khanna, Udit
name: Rao, Sumathi
name: Kundu, Arijit
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We propose a setup for the experimental realization of unexpected and anisotropic $0$-$π$ transitions of the Josephson current, in a junction whose link is made of irradiated Weyl semi-metal (WSM), due to the presence of chiral nodes. We show using a Green's function technique that the Josephson current through a time-reversal symmetric WSM has anisotropic periodic oscillations as a function of $k_0L$, where $k_0$ is the (relevant) separation of the chiral nodes and $L$ is the length of the sample. This is unexpected, for time-reversal symmetric systems, although it has been shown earlier for time-reversal symmetry breaking WSMs. We then show that the effective value of $k_0$ can be tuned with precision by irradiating the sample with photons resulting in $0$-$π$ transitions of the critical current. Finally, we discuss the robustness of our setup.
Mass differences and neutron pairing in Ca, Sn and Pb isotopes
Creators: name: Ishkhanov, B. S.
name: Sidorov, S. V.
name: Tretyakova, T. Yu.
name: Vladimirova, E. V.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Nuclear Theory (nucl-th)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: Various estimates of the even-odd effect of the mass shell of atomic nuclei are considered. Based on the experimental mass values of the Ca, Sn, and Pb isotopes, the dependence of the energy gap on the neutrons number is traced and the relationship of this characteristic to the properties of external neutron subshells is shown. In nuclei with closed proton shells, effects directly related to neutron pairing and effects of nucleon shells are discussed.
description: corrected typos
Optical Levitation of a Mirror for Reaching the Standard Quantum Limit
Creators: name: Michimura, Yuta
name: Kuwahara, Yuya
name: Ushiba, Takafumi
name: Matsumoto, Nobuyuki
name: Ando, Masaki
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We propose a new method to optically levitate a macroscopic mirror with two vertical Fabry-P{é}rot cavities linearly aligned. This configuration gives the simplest possible optical levitation in which the number of laser beams used is the minimum of two. We demonstrate that reaching the standard quantum limit (SQL) of a displacement measurement with our system is feasible with current technology. The cavity geometry and the levitated mirror parameters are designed to ensure that the Brownian vibration of the mirror surface is smaller than the SQL. Our scheme provides a promising tool for testing macroscopic quantum mechanics.
description: 5 pages, 2 figures
Unlocking Knowledge: National Mandate for Institutional Copyright Retention to Enable Open Access in India
Creators: name: Koley, Moumita
Publisher: name: Zenodo
Year: 2024
Subjects: subject: open access
subject: open science
subject: right retaintion
subject: green OA
subject: India
subject: Science and technology studies
subject: science policy

description: This brief strongly advocates for implementing a mandatory institutional right-retention policy across all publicly funded institutions in India. This policy would enable immediate self-archiving by allowing authors to retain primary rights over their work. This crucial reform ensures that results from publicly funded research are made open access through institutional or national repositories immediately upon publication. It is essential to empower institutions to dismantle the prohibitive subscription barriers imposed by traditional journals, ensuring the broad dissemination of research funded by public money. Current discussions on open access predominantly focus on the APC-based gold open-access model, which introduces high costs for authors—a significant barrier in resource-constrained countries. There is an urgent need for assertive actions that guarantee unrestricted access to publicly funded research. India offers a vast landscape of opportunities to champion open access by promoting self-archiving in institutional and national repositories. However, the common practice of transferring copyright ownership to journals critically hampers the immediate implementation of such practices as well as the broader use of knowledge. To address this, it is imperative to enforce national mandates that ensure authors' institutions retain primary rights, relegating only secondary rights to publishers. Implementing such policies would catalyse a systemic transformation, reinforcing the ethos of freely accessible and utilizable knowledge for the greater societal good.
The origin of the very metal-rich stars near the sun
Creators: name: Mondal, Ankita
Publisher: name: Zenodo
Year: 2023
Subjects: Surveys within the Milky Way and Nearby Galaxies

description: Stars of all ages are found near the sun- young and old, with abundances up to about [Fe/H] = 0.5. The most metal-rich stars with [Fe/H] > 0.1, could not have formed near the sun, because the ISM near the sun is not so metal-rich. It is widely believed that they formed in the inner Galaxy and migrated out to the solar neighborhood via radial migration. The migration process moves stars from near-circular orbits at one radius to near-circular orbits at another (mostly larger) radius via transient spiral structures, and their vertical dispersion is lower after the migration, due to the conservation of z-action. From the APOGEE, GALAH, and Gaia surveys, we study the abundances and motions of stars with [Fe/H] > 0.1 near the sun. We look for chemical and dynamical properties of these stars that give insights into their possible origin in the inner Galaxy. From their (Vphi, VR) distribution, some of these metal-rich stars are associated with the Hercules moving group of stars, trapped by the Galactic bar in stable orbits. These orbits carry the stars out into the solar neighborhood. Our analysis supports this view. Unlike the stars of near-solar abundance, we find no change in orbital eccentricity distribution for the metal-rich stars. These stars have had a common dynamical history since their birth in the inner Galaxy.
Characterization of measurement-induced phase transitions in random quantum circuits
Creators: name: Zabalo, Aidan
Publisher: name: No Publisher Supplied
Year: 2022

description: Recently, a new class of nonequilibrium quantum phase transitions was identified in random quantum circuits undergoing unitary evolution interspersed with local projective measurements.The transition is characterized by a change in the scaling of the entanglement entropy from volume-law to area-law scaling as the measurement rate $p$ is increased above a critical value $p_c$.In this thesis, we propose the tripartite mutual information as an unbiased diagnostic of the transition that has weak finite-size effects and simple scaling properties.Using this quantity we locate the critical point of the transition for a collection of models and uncover that the critical exponents characterizing the transition are numerically similar between the generic Haar and stabilizer circuit models as well as 2-D bond percolation. To distinguish between the different universality classes of measurement-induced criticality we use a numerical transfer matrix method to calculate the effective central charge of the logarithmic conformal field theory at the critical point as well as the first few low-lying scaling dimensions of operators in the theory.Our results provide convincing evidence that the generic (Haar) and Clifford transition in qubit models lie in different universality classes and are distinct from the percolation transition for qudits in the limit of large onsite Hilbert space dimension.Importantly, in the generic qubit model, we find evidence of multifractal scaling of correlation functions indicating a continuous spectrum of scaling dimensions at the critical point, which are absent in the percolation limit. We then proceed to modify the structure of the dynamics by introducing symmetry, quasiperiodicity, and disorder. For dynamics conserving a $U(1)$ global charge we identify a new charge-sharpening transition within the volume-law entangled phase.For dynamics with quasiperiodicity in the measurement rate we find the critical properties remain unchanged consistent with the expectation from the Luck criterion.On the other hand, for dynamics with disorder in the measurement rate, we find evidence of a new universality class as predicted by the Harris criterion, and signatures of an infinite randomness fixed point.Our results represent a significant step forward in the characterization of models of measurement-induced criticality.
A Robust BAO Extractor
Creators: name: Noda, Eugenio
name: Peloso, Marco
name: Pietroni, Massimo
Publisher: name: arXiv
Year: 2017
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We define a procedure to extract the oscillating part of a given nonlinear Power Spectrum, and derive an equation describing its evolution including the leading effects at all scales. The intermediate scales are taken into account by standard perturbation theory, the long range (IR) displacements are included by using consistency relations, and the effect of small (UV) scales is included via effective coefficients computed in simulations. We show that the UV effects are irrelevant in the evolution of the oscillating part, while they play a crucial role in reproducing the smooth component. Our "extractor" operator can be applied to simulations and real data in order to extract the Baryonic Acoustic Oscillations (BAO) without any fitting function and nuisance parameter. We conclude that the nonlinear evolution of BAO can be accurately reproduced at all scales down to $z=0$ by our fast analytical method, without any need of extra parameters fitted from simulations.
description: Published version, 20 pages, 8 figures
Disproof of a widely-accepted mathematical conjecture
Creators: name: Wang, Changbiao
Publisher: name: arXiv
Year: 2016
Subjects: subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences
subject: 78A25, 83

description: A mathematical conjecture is successfully identified, which is used for relativistic analysis of dielectric Einstein-box thought experiment in a Letter (Ramos, Rubilar, and Obukhov, Phys. Lett. A 375, 1703 (2011)), where the authors conjecture (without any citations) that, the symmetry and divergence-less property of a Lorentz 4-tensor is a sufficient condition for the time-column space integrals to constitute a Lorentz 4-vector. This mathematical conjecture has been thought to be "a mathematical fact the validity of which was shown well" in textbooks. However in this paper, we indicate that this conjecture has never been proved mathematically. By enumerating a counterexample, we find that this mathematical conjecture is flawed, and it is not persuasive to use a flawed mathematical conjecture as a starting point to resolve Abraham-Minkowski controversy over light momentum in a dielectric medium. We also indicate that this flawed mathematical conjecture is actually a widely-accepted conjecture in the dynamics of relativity in textbooks for many decades. To eliminate a misunderstanding of this flawed conjecture in the community, we provide a detailed elucidation of why Møller's mathematical statement, also called "Møller's version of von Laue's theorem", only defines a trivial zero 4-vector for an electromagnetic stress-energy Lorentz 4-tensor.
description: This arXiv copy of manuscript is the final version submitted to Optik for production. In the Optik produced copy (http://dx.doi.org/10.1016/j.ijleo.2017.05.003), there are quite a few typos in math formulas after copyedited, somehow with author's proof corrections not considered. 4 papers, no figures, 8 references
Efficient and Adaptive Linear Regression in Semi-Supervised Settings
Creators: name: Chakrabortty, Abhishek
name: Cai, Tianxi
Publisher: name: arXiv
Year: 2017
Subjects: subject: Methodology (stat.ME)
subject: Statistics Theory (math.ST)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics
subject: 62F35, 62J05, 62F10, 62F12, 62G08

description: We consider the linear regression problem under semi-supervised settings wherein the available data typically consists of: (i) a small or moderate sized 'labeled' data, and (ii) a much larger sized 'unlabeled' data. Such data arises naturally from settings where the outcome, unlike the covariates, is expensive to obtain, a frequent scenario in modern studies involving large databases like electronic medical records (EMR). Supervised estimators like the ordinary least squares (OLS) estimator utilize only the labeled data. It is often of interest to investigate if and when the unlabeled data can be exploited to improve estimation of the regression parameter in the adopted linear model. In this paper, we propose a class of 'Efficient and Adaptive Semi-Supervised Estimators' (EASE) to improve estimation efficiency. The EASE are two-step estimators adaptive to model mis-specification, leading to improved (optimal in some cases) efficiency under model mis-specification, and equal (optimal) efficiency under a linear model. This adaptive property, often unaddressed in the existing literature, is crucial for advocating 'safe' use of the unlabeled data. The construction of EASE primarily involves a flexible 'semi-non-parametric' imputation, including a smoothing step that works well even when the number of covariates is not small; and a follow up 'refitting' step along with a cross-validation (CV) strategy both of which have useful practical as well as theoretical implications towards addressing two important issues: under-smoothing and over-fitting. We establish asymptotic results including consistency, asymptotic normality and the adaptive properties of EASE. We also provide influence function expansions and a 'double' CV strategy for inference. The results are further validated through extensive simulations, followed by application to an EMR study on auto-immunity.
description: 51 pages; Revised version - to appear in The Annals of Statistics
Understanding the newly observed $Ω_c$ states through their decays
Creators: name: Wang, Kai-Lei
name: Xiao, Li-Ye
name: Zhong, Xian-Hui
name: Zhao, Qiang
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The strong and radiative decay properties of the low-lying $Ω_c$ states are studied in a constituent quark model. We find that the newly observed $Ω_c$ states by the LHCb Collaboration can fit in well the decay patterns. Thus, their spin-parity can be possibly assigned as the following: (i) The $Ω_c(3000)$ has $J^P=1/2^-$ and corresponds to the narrow $1P$ mixed state $|1^2P_λ\frac{1}{2}^-\rangle_1$, its partner $|1^2P_λ\frac{1}{2}^-\rangle_2$ should be a broad state with a width of $\sim 100$ MeV. (ii) The $Ω_c(3050)$ and $Ω_c(3066)$ can be assigned to be two $J^P=3/2^-$ states, $|1^4P_λ\frac{3}{2}^-\rangle$ and $|1^2P_λ\frac{3}{2}^-\rangle$, respectively. (iii) The $Ω_c(3090)$ can be assigned as the $|1^4P_λ\frac{5}{2}^-\rangle$ state with $J^P=5/2^-$. (iv) The $Ω_c(3119)$ might correspond to one of the two $2S$ states of the first radial excitations, i.e. $|2^2S_{λλ}\frac{1}{2}^+\rangle$ or $|2^4S_{λλ}\frac{3}{2}^+\rangle$.
description: 7 pages, 4 figures. To appear in PRD
A Linear System of Differential Equations Related to Vector-Valued Jack Polynomials on the Torus
Creators: name: Dunkl, Charles F.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: 33C52, 20C30, 35F35, 46G10, 42B10

description: For each irreducible module of the symmetric group $\mathcal{S}_{N}$ there is a set of parametrized nonsymmetric Jack polynomials in $N$ variables taking values in the module. These polynomials are simultaneous eigenfunctions of a commutative set of operators, self-adjoint with respect to two Hermitian forms, one called the contravariant form and the other is with respect to a matrix-valued measure on the $N$-torus. The latter is valid for the parameter lying in an interval about zero which depends on the module. The author in a previous paper [SIGMA 12 (2016), 033, 27 pages, arXiv:1511.06721] proved the existence of the measure and that its absolutely continuous part satisfies a system of linear differential equations. In this paper the system is analyzed in detail. The $N$-torus is divided into $(N-1)!$ connected components by the hyperplanes $x_{i}=x_{j}$, $i
Jacobi method for symmetric $4\times4$ matrices converges for every cyclic pivot strategy
Creators: name: Begovic, Erna
name: Hari, Vjeran
Publisher: name: arXiv
Year: 2017
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 65F15

description: The paper studies the global convergence of the Jacobi method for symmetric matrices of size $4$. We prove global convergence for all $720$ cyclic pivot strategies. Precisely, we show that inequality $S(A^{[t+3]})\leqγS(A^{[t]})$, $t\geq1$, holds with the constant $γ<1$ that depends neither on the matrix $A$ nor on the pivot strategy. Here $A^{[t]}$ stands for the matrix obtained from $A$ after $t$ full cycles of the Jacobi method and $S(A)$ is the off-diagonal norm of $A$. We show why three consecutive cycles have to be considered. The result has a direct application on the $J$-Jacobi method.
description: 16 pages
QCD leading order study of the $J/ψ$ leptoproduction at HERA within the nonrelativistic QCD framework
Creators: name: Sun, Zhan
name: Zhang, Hong-Fei
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: As indicated in our previous paper (Phys.Rev.D96.034002), the existing literatures studying the $J/ψ$ production in deeply inelastic scattering (DIS) in collinear factorization are on the basis of a formalism that will lead to wrong results when the ranges of the transverse momentum or the rapidity of the $J/ψ$ in the laboratory frame do not cover all values possible for them. In this paper, we present the renewed results for the $J/ψ$ production in DIS at HERA within the nonrelativistic QCD framework at QCD leading order (LO). Three different sets of the long-distance matrix elements are employed for comparison. The predictions via the colour-singlet (CS) model at QCD LO are generally below the experimental data especially in the regions where perturbation theory are expected to work well, while the colour-octet contributions are of the same order of magnitude as the CS ones, however, in general make the agreement between theory and experiment better.
Two-qubit entangling gates between distant atomic qubits in a lattice
Creators: name: Cesa, A.
name: Martin, J.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Arrays of qubits encoded in the ground-state manifold of neutral atoms trapped in optical (or magnetic) lattices appear to be a promising platform for the realization of a scalable quantum computer. Two-qubit conditional gates between nearest-neighbor qubits in the array can be implemented by exploiting the Rydberg blockade mechanism, as was shown by D. Jaksch et al. [Phys. Rev. Lett. 85, 2208 (2000)]. However, the energy shift due to dipole-dipole interactions causing the blockade falls off rapidly with the interatomic distance and protocols based on direct Rydberg blockade typically fail to operate between atoms separated by more than one lattice site. In this work, we propose an extension of the protocol of Jaksch \emph{et al.}\ for controlled-Z and controlled-NOT gates which works in the general case where the qubits are not nearest-neighbor in the array. Our proposal relies on the Rydberg excitation hopping along a chain of ancilla non-coding atoms connecting the qubits on which the gate is to be applied. The dependence of the gate fidelity on the number of ancilla atoms, the blockade strength and the decay rates of the Rydberg states is investigated. A comparison between our implementation of distant controlled-NOT gate and one based on a sequence of nearest-neighbor two-qubit gates is also provided.
description: 13 pages, 7 figures
title: Sozialistischer Bildertausch: Analoge und digitale Quellenarbeit. Ein Interview mit Annette Vowinckel
Creators: name: Vowinckel, Annette
name: Ferreira dos Santos, Janaina
name: Sucutardean, Iulia-Maria
Publisher: name: ZZF - Leibniz-Zentrum für Zeithistorische Forschung: Visual History
Year: 2023

description: Annette Vowinckel ist Leiterin der Abteilung Zeitgeschichte der Medien- und Informationsgesellschaft am Leibniz-Zentrum für Zeithistorische Forschung in Potsdam und außerplanmäßige Professorin im Institut für Geschichtswissenschaften an der Humboldt-Universität zu Berlin. Im von Janaina Ferreira dos Santos und Iulia Sucutardean geführten multimedialen Interview für das Online-Portal „Visual History“ (visual-history.de) stellt die Historikerin ihr neues Buchprojekt Zentralbild, Photo International and the Visual Politics of Late State Socialism vor, geht auf die Methoden ihrer Quellenarbeit ein und betont, wie digitale Tools die Arbeit von Historiker:innen in vielerlei Hinsicht vereinfachen können.