cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Localization and Duality for ABJM Latitude Wilson Loops
Creators: name: Griguolo, Luca
name: Guerrini, Luigi
name: Yaakov, Itamar
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We investigate several aspects of BPS latitude Wilson loops in gauge theories in three dimensions with $\mathcal{N}\ge 4$ supersymmetry. We derive a matrix model for the bosonic latitude Wilson loop in ABJM using supersymmetric localization, and show how to extend the computation to more general Chern-Simons-matter theories. We then define latitude type Wilson and vortex loop operators in theories without Chern-Simons terms, and explore a connection to the recently derived superalgebra defining local Higgs and Coulomb branch operators in these theories. Finally, we identify a BPS loop operator dual to the bosonic latitude Wilson loop which is a novel bound state of Wilson and vortex loops, defined using a worldvolume supersymmetric quantum mechanics.
description: 51 pages; typos corrected, references added, comments added
Quantum gravity and elementary particles from higher gauge theory
Creators: name: Radenkovic, Tijana
name: Vojinovic, Marko
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We give a brief overview how to couple general relativity to the Standard Model of elementary particles, within the higher gauge theory framework, suitable for the spinfoam quantization procedure. We begin by providing a short review of all relevant mathematical concepts, most notably the idea of a categorical ladder, 3-groups and generalized parallel transport. Then, we give an explicit construction of the algebraic structure which describes the full Standard Model coupled to Einstein-Cartan gravity, along with the classical action, written in the form suitable for the spinfoam quantization procedure. We emphasize the usefulness of the 3-group concept as a superior tool to describe gauge symmetry, compared to an ordinary Lie group, as well as the possibility to employ this new structure to classify matter fields and study their spectrum, including the origin of fermion families.
description: Proceedings of the Workshop on Quantum Fields and Nonlinear Phenomena, Craiova, Romania, 2020. 14 pages
Discovery of X-ray emission from the young radio pulsar PSR J1357-6429
Creators: name: Esposito, P.
name: Tiengo, A.
name: De Luca, A.
name: Mattana, F.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present the first X-ray detection of the very young pulsar PSR J1357-6429 (characteristic age of 7.3 kyr) using data from the XMM-Newton and Chandra satellites. We find that the spectrum is well described by a power-law plus blackbody model, with photon index Gamma=1.4 and blackbody temperature kT=160 eV. For the estimated distance of 2.5 kpc, this corresponds to a 2-10 keV luminosity of about 1.2E+32 erg/s, thus the fraction of the spin-down energy channeled by PSR J1357-6429 into X-ray emission is one of the lowest observed. The Chandra data confirm the positional coincidence with the radio pulsar and allow to set an upper limit of 3E+31 erg/s on the 2-10 keV luminosity of a compact pulsar wind nebula. We do not detect any pulsed emission from the source and determine an upper limit of 30% for the modulation amplitude of the X-ray emission at the radio frequency of the pulsar.
description: Revised version (minor changes in text and figures). Accepted for publication on Astronomy and Astrophysics Letters on 10/04/2007
Resonant activation in bistable semiconductor lasers
Creators: name: Lepri, Stefano
name: Giacomelli, Giovanni
Publisher: name: arXiv
Year: 2007
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We theoretically investigate the possibility of observing resonant activation in the hopping dynamics of two-mode semiconductor lasers. We present a series of simulations of a rate-equations model under random and periodic modulation of the bias current. In both cases, for an optimal choice of the modulation time-scale, the hopping times between the stable lasing modes attain a minimum. The simulation data are understood by means of an effective one-dimensional Langevin equation with multiplicative fluctuations. Our conclusions apply to both Edge Emitting and Vertical Cavity Lasers, thus opening the way to several experimental tests in such optical systems.
description: Submitted to Phys. Rev. A
Cold Disks: Spitzer Spectroscopy of Disks around Young Stars with Large Gaps
Creators: name: Brown, J. M.
name: Blake, G. A.
name: Dullemond, C. P.
name: Merin, B.
name: Augereau, J. C.
name: Boogert, A. C. A.
name: Evans, N. J.
name: II
name: Geers, V. C.
name: Lahuis, F.
name: Kessler-Silacci, J. E.
name: Pontoppidan, K. M.
name: van Dishoeck, E. F.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We have identified four circumstellar disks with a deficit of dust emission from their inner 15-50 AU. All four stars have F-G spectral type, and were uncovered as part of the Spitzer Space Telescope ``Cores to Disks'' Legacy Program Infrared Spectrograph (IRS) first look survey of ~100 pre-main sequence stars. Modeling of the spectral energy distributions indicates a reduction in dust density by factors of 100-1000 from disk radii between ~0.4 and 15-50 AU, but with massive gas-rich disks at larger radii. This large contrast between the inner and outer disk has led us to use the term `cold disks' to distinguish these unusual systems. However, hot dust [0.02-0.2 Mmoon] is still present close to the central star (R ~0.8 AU). We introduce the 30/13 micron, flux density ratio as a new diagnostic for identifying cold disks. The mechanisms for dust clearing over such large gaps are discussed. Though rare, cold disks are likely in transition from an optically thick to an optically thin state, and so offer excellent laboratories for the study of planet formation.
description: 13 pages, 3 figures, accepted to ApJL
Quark matter and the astrophysics of neutron stars
Creators: name: Prakash, M
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Some of the means through which the possible presence of nearly deconfined quarks in neutron stars can be detected by astrophysical observations of neutron stars from their birth to old age are highlighted.
description: 8 pages, 6 figures, Plenary talk in Quark Matter 2006 to appear in J. Phys. G: Nucl. Part. Phys. 34 (2007)
VP13-03: A fabrication process of Fe-Ni films electroplated from gel electrolyte
Creators: Takeshi Yanai
Yusuke Matsumoto
Kota Shiraki
Runa Hosohata
Yuka Yamaguchi
Akihiro Yamashita
Masaki Nakano
Hirotoshi Fukunaga
Publisher: name: IEEE
Year: 2023

Soft Magnetic Materials (Virtual)
Typical-used electroplating electrolytes for magnetic films are aqueous solutions (liquid electrolytes), and we have already reported some electroplated Fe-Ni films using aqueous solutions [1-4]. Recently, environmental awareness has been raised, and we need to pay attention to environmental loads for the fabrication process. For electroplating, waste reduction is one of the actions to reduce environmental loads. In the present study, we proposed a fabrication process of electroplating soft magnetic films of Ni and Fe-Ni alloys using a gel electrolyte and investigated the magnetic properties of the films. Table 1 shows the bath conditions. We prepared a liquid electrolyte by stirring the water with the reagents at 50°C until the reagent was completely dissolved. After that, we added 23 g/L of gelatin to the liquid electrolyte and stirred for approximately 7 min at 60°C, and then the electrolyte was cooled for more than 60 min in a freezer. Figure 1 shows hysteresis loops of as-plated Fe-Ni films prepared from the gel electrolyte. The inset indicates a photograph of the cooled plating baths. As shown in Fig.1, saturation magnetization increased with the Fe content in the film. This result implies that Fe-Ni alloy films could be obtained. Gel electrolytes can be kept in their shapes without the beaker used as a vessel, indicating that electroplating flexibility is higher than liquid ones. Therefore, we concluded that electroplating Fe-Ni films using the gel electrolyte is an attractive fabrication process.References: [1] H. L. Seet, X. P. Li, J. B. Yi, W. Y. Ooi, and K. S. Lee, “Effect of deposition methods on the magnetic properties of nanocrystalline permalloy,” J. Alloys Compd., 449 (2008) 284. [2] B. Koo and B. Yoo, “Electrodeposition of low-stress NiFe thin films from a highly acidic electrolyte,” Surf. Coat. Technol., 205 (2010) 740. [3] J. L. McCrea, G. Palumbo, G. D. Hibbard, and U. Erb, “Properties and applications for electrodeposited nanocrystalline Fe-Ni alloys,” Rev.Adv. Sci., 5 (2003) 252. [4] T. Shimokawa, T. Yanai, K. Takahashi, M. Nakano, K. Suzuki, and H. Fukunaga, “Soft magnetic properties of electrodeposited Fe-Ni films prepared in citric acid based bath,” IEEE Trans. Magn., 48, (2012) 2907.
The Quasar Accretion Disk Size - Black Hole Mass Relation
Creators: name: Morgan, Christopher W.
name: Kochanek, C. S.
name: Morgan, Nicholas D.
name: Falco, Emilio E.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We use the microlensing variability observed for nine gravitationally lensed quasars to show that the accretion disk size at 2500 Angstroms is related to the black hole mass by log(R_2500/cm) = (15.6+-0.2) + (0.54+-0.28)log(M_BH/10^9M_sun). This scaling is consistent with the expectation from thin disk theory (R ~ M_BH^(2/3)), but it implies that black holes radiate with relatively low efficiency, log(eta) = -1.29+-0.44 + log(L/L_E) where eta=L/(Mdot c^2). These sizes are also larger, by a factor of ~3, than the size needed to produce the observed 0.8 micron quasar flux by thermal radiation from a thin disk with the same T ~ R^(-3/4) temperature profile. More sophisticated disk models are clearly required, particularly as our continuing observations improve the precision of the measurements and yield estimates of the scaling with wavelength and accretion rate.
description: 5 pages, 3 figures, submitted to ApJL
GB-06: Magneto-optical detection of spin-orbit torque vector with first-order Kerr effects
Creators: Claudio Gonzalez-Fuentes
Marian Abellan and Simon Oyarzun
Publisher: name: IEEE
Year: 2023

Microscopy & Characterization III: Spin Textures, Magnetic Interactions, Nanoparticle Dynamics and X-ray Methods
When spin-polarized currents diffuse into a ferromagnetic (FM) material, they induce spin-orbit torques (SOTs): a powerful mechanism for magnetic order manipulation with applications in magnetic recording, logic devices, and neuro-morphing computing [1]. To date, detection SOTs have relied almost exclusively on measuring electrical voltages arising from the device under excitation. In this line, techniques such as second harmonic generation, spin transfer torque ferromagnetic resonance (STT-FMR), and spin pumping have dominated the scene. In these techniques, signals are often contaminated by unwanted thermo-electric voltages. Also, the sensitivity depends critically on magneto-electric coefficients showing large variations even for typical 3d ferromagnetic materials [2]. This work presents a powerful new method for detecting SOTs based on Magneto-Optical Kerr Effect (MOKE). We can quantify the damping-like and field-like SOT effective fields (hDL and hFL, respectively) of SOTs, employing a simple and low-cost set-up that has already been widely employed in MOKE magnetometry (Fig. 1). We tested our method in NiFe/Pt, NiFe/Pd, and Ta/CoFeB bilayers, obtaining a damping-like SOT efficiency (ζDL) equal to 0.08 ± 0.01, 0.034 ± 0.004 and -0.15 ± 0.01 respectively. On the other side, we obtained hFL\hDL ratios equal to 0.24 ± 0.03 and 0.11 ± 0.03 in the samples with 4 nm thick NiFe and CoFeB, respectively. The results for ζDL are close to the most accepted values reported in the literature for the studied materials. The hFL\hDL ratios fit well inside the diffusive model of spin accumulation in the ferromagnetic layer [3], with a finite spin dephasing length. This effect has often been disregarded in STT-FMR works.References: [1] A. Hiroata et al., J. Magn. Magn. Mater. 509, 166711 (2017). [2] M.-H. Nguyen and C.-F. Pai, APL Materials 9, 030902 (2021). [3] S. Zhang, P. M. Levy, and A. Fert, Phys. Rev. Lett. 88, 236601 (2002).
VP12-11: Research on the Relationship between the Distribution of High-Permeability Materials of Rotors and Characteristics of Magnetic Field in Machines
Creators: Xiaoyu Liang
Mingqiao Wang
Ping Zheng
Jialin Gao
Wanquan Li
Publisher: name: IEEE
Year: 2023

Sensors, High Frequency Devices, and Power Devices (Virtual)
Synchronous reluctance machine (SRM) can achieve high torque-density and low torque ripple through reasonable design in reluctance machine. Compared with permanent magnet synchronous machine, SRM does not need expensive permanent magnet and has low cost. However, the rotor of SRM with many structural parameters is complex, and the design takes a long time. Many problems about the design and optimization of SRM have been studied and analyzed to improve the design efficiency and performance. [1] The magnetic barrier limits and guides the direction of the flux in machine. The width, start and end of magnetic barrier affect the modulation effect of the magnetic conductivity harmonic of rotor on the magnetomotive force of winding. The magnetic field harmonics, torque characteristics, loss, and other performances of machine will change as the rotor structure with above different parameters changes. Take conventional SRM as an example for analysis, as shown in Fig. 1. The energy conversion principle of machine with saliency can be obtained by using the energy method. Under the action of magnetic barrier with four shapes, the magnetic fields are shown in Fig. 2 (a), (b). The magnetic field distribution at d- and q-axis are basically consistent under magnetic barrier of different shapes. This indicates that when the load does not saturate the iron corn, the shape of the magnetic barrier does not affect the distribution and harmonic of the magnetic field, which is mainly related to the starting and ending positions of the magnetic barrier. Considering the influence of different loads, the design rules and constraints for the shape of magnetic barrier can be given. The influence and rules of magnetic barrier with different spatial distributions on harmonics of magnetic field is analyzed. As the number of magnetic barrier layers increases from 1 to 3, the growth rate of the maximum of difference between the d- and q-axis magnetic fields slows down, which can be quickly obtained by analyzing model. So, design efficiency and performance of SRM will be improved.References: [1] Y. Bao, M. Degano and S. Wang, et al., "A Novel Concept of Ribless Synchronous Reluctance Motor for Enhanced Torque Capability,” IEEE Trans. Ind. Electron., vol. 67, no. 4, pp. 2553-2563 (2019)
Complexity measures and occurrence of the breaking point in the neutron and gamma-rays time series measured with organic scintillators
Creators: name: Mihailovic, Dragutin
name: Avdic, Senada
name: Mihailovic, Anja
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: This paper deals with the first analysis of the neutron and gamma time series measured with organic scintillators from plutonium samples by using information measures. Fast neutron detection with organic scintillators has been widely used for various nuclear applications and homeland security. One of the significant attributes of special nuclear materials (SNM) is the high multiplicity events in a short period of time. The time distributions of neutron and gamma-rays events for the plutonium metal plates designed as fuel plates for the Idaho National Laboratory (INL) Zero Power were measured with the Fast Neutron Multiplicity Counter (FNMC) consisting of 8 EJ-309 liquid scintillators and 8 stilbene detectors. Since the neutron correlated counts within the coincidence window of 40 ns are related to 240Pu effective mass of plutonium metal plates we investigated the randomness of the measured neutron and gamma-rays events. To access such information, we resort to complexity measures in the hope of being able to connect complexity values with the reliability of detection. That was done through (i) application of Kolmogorov complexity (KC) and its derivatives [Kolmogorov spectrum and its highest value (KCM) and running complexity (RKC)] and (ii) establishing the breaking point after which there exists a sharp drop in the running Kolmogorov complexity of the neutron and gamma-rays time series. It was found that the complexity of all the time series detected from the sample with 5, 9, 11, 13, and 15 plutonium plates had the high almost identical values of KC while the sample with 3 plates had by one-third smaller KC values than all the others. These calculations were supplemented by the Lypaunov exponents for a time series and the NIST tests. The low KC values can be addressed to the different sources of uncertainties in measuring procedure with the sample consisting of three plates.
description: 37 pages, 12 figures
GG-06: Bit-Island Arrangement and Signal Processing in Double-Layer Magnetic Recording Technology
Creators: V. Sawangarom
C. Buajong
K. Kankhunthod
and C. Warisarn
Publisher: name: IEEE
Year: 2023

Magnetic Recording
To overcome the superparamagnetic limitation [1]-[2] that is the barrier to increasing the areal density (AD) of perpendicular magnetic recording technology, bit-patterned magnetic recording (BPMR) has been presented and applied together with the double layer magnetic recording (DLMR) [3]-[5]. Those works reveal the possibility and potential of DLMR to continuously increase AD. In this work; therefore, we first propose a DLMR structure that is designed based on bit-patterned media as shown in Fig. 1. The bit islands are aligned with a rectangular grid but the relative positions of each layer were shifted at the along- and cross-track directions by Tx/2 and Tz/2, respectively. On the top view, we have staggered-like recording media [6]. Then, we also present the use of an array reader that consists of three readheads in reading process, the way to retrieve all three readback signals will be described. The first (H1) and third (H3) readheads are positioned at the center of the l-th and l+2-th tracks (upper layer), respectively. The second readhead (H2) is positioned over the middle of the l+1-th track (lower layer). To evaluate the BER performance between our proposed media design under equivalent AD of 4.0 Tb/in2 (2.0+2.0 Tb/in2) denoted by “Prop. System” with the conventional single-layer bit-patterned media under AD of 4.0 Tb/in2 denoted by “Conv. System” as shown in Fig. 2. BER performances of the 1st, 2nd, and 3rd tracks are denoted by “Prop. System. H1 (UL)”, “Prop. System. H2 (LL),” and “Prop. System. H3 (UL), respectively. The average BER of three data tracks is denoted by “Prop. System. Avg.” The BER performances of the 1st and 3rd tracks are great because of lower ITI interference. On the other hand, the performance of the 2nd track is degraded by ILI effect. It implies that the proposed media structure based on a double-layer magnetic recording can enhance performance. Moreover, in this work, the optimal diameter of bit islands for each layer and the coding schemes will be also examined for avoiding ISI, ITI, and ILI effects.References: [1] C. Ross, Annual Review of Materials Research, 31(1). pp. 203-235 (2001) [2] R. L. White et al., IEEE Trans. Magn., pp. 990-995 (1997) [3] Y. Nakamura et al., 2021 IEEE INTERMAG, LYON, France, pp. 1-5 (2021) [4] H. Saito, IEEE Trans. Magn., 59(3), 3000810 (2023) [5] Y. Nakamura et al., IEEE Trans. Magn., 58, pp. 1-5 (2022) [6] Y. Ng et al., IEEE Trans. Magn. 48(6), pp. 1976-1983 (2012)
The Nature of Stellar Winds in the Star-Disk Interaction
Creators: name: Matt, Sean
name: Pudritz, Ralph E.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Stellar winds may be important for angular momentum transport from accreting T Tauri stars, but the nature of these winds is still not well-constrained. We present some simulation results for hypothetical, hot (~1e6 K) coronal winds from T Tauri stars, and we calculate the expected emission properties. For the high mass loss rates required to solve the angular momentum problem, we find that the radiative losses will be much greater than can be powered by the accretion process. We place an upper limit to the mass loss rate from accretion-powered coronal winds of ~1e-11 solar masses per year. We conclude that accretion powered stellar winds are still a promising scenario for solving the stellar angular momentum problem, but the winds must be cool (~1e4 K) and thus are not driven by thermal pressure.
description: 7 pages, including 2 figures. To appear in proceedings of IAU Symposium No. 243: Star-Disk Interaction in Young Stars
VP9-10: The Novel CPU Cache Architecture of MTJ based on Two-Dimensional Ferromagnetic Crystal
Creators: Shaopu Han
Yanfeng Jiang
Publisher: name: IEEE
Year: 2023

Magnetoresistance and Associated Effects (Virtual)
Two-dimensional van der Waals ferromagnets have excellent controllable ferromagnetism and scalability for non-volatile information memory based on spintronics. In recent years, the exploration of advanced two-dimensional materials such as MoS2 and Fe3GeTe2 (FGT) has contributed a novel platform for the realization of spintronics storage [1-3]. FGT based on van der Waals layered structure exhibits excellent electromagnetic physical properties such as two-dimensional intrinsic ferromagnetism, large magnetic anisotropy, high-quality surfaces, large coercivity, and high Curie temperature. It is widely probed for information processing and storage computing [4]. The FGT-based Magnetic Tunnel Junction (MTJ) device has a huge TMR value [5], which is promising to mitigate the read/write interference and enhance the sensing margin in the magnetic random access memory (MRAM) cell circuit. Therefore it is of paramount significance for storage applications. In this paper, a novel Spin-Orbit Transfer (SOT)-MRAM composed of FGT is employed as a storage medium in the computer architecture, as shown in Fig.1. It forms a hybrid storage (L1, L2, Last Level Cache) with conventional SOT-MRAM and Spin Transfer Torque (STT)-MRAM, replacing the original static random access memory (SRAM) in the novel triple-level CPU cache architecture. This can override the increasing leakage problem of SRAM, while opening up the application of non-volatile storage technology in computer systems to the L1 cache level, as shown in Fig. 2. Traditional MRAM suffers from various problems such as poor integration and low flip rate at the L1cache. FGT addresses these deficiencies. Meanwhile, this paper proposes various cache optimization schemes for magnetic memory to better match the performance of FGT-SOT-MRAM to CPU. As shown in Fig.2, the simulation results demonstrate that the FGT-based MRAM can achieve up to 54.41% energy optimization in the CPU cache system compared to the conventional MRAM.References: [1] Kim. T.H., Han. S.H. and Cho. B.K. , Commun. Phys, vol. 2, p. 41 ( 2019). [2] Zhao. M., Zhao. Y. and Xi. Y. et al., Nano Lett., vol. 21, p. 9233–9239 (2021). [3] Xu. C., Li. X. and Chen. P. et al., Adv. Mater, vol. 34, p. 2107779 (2022). [4] May. A.F., Ovchinnikov. D. and Zheng. Q. et al., ACS Nano, vol. 13, p. 4436–4442 (2019). [5] Jiang. M., Asahara. H. and Sato. S. et al., Nat. Electron, vol. 3, p. 751–756 (2020).
Chandra Observations of Supernova 1987A
Creators: name: Park, Sangwook
name: Burrows, David N.
name: Garmire, Gordon P.
name: McCray, Richard
name: Racusin, Judith L.
name: Zhekov, Svetozar A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We have been monitoring Supernova (SN) 1987A with {\it Chandra X-Ray Observatory} since 1999. We present a review of previous results from our {\it Chandra} observations, and some preliminary results from new {\it Chandra} data obtained in 2006 and 2007. High resolution imaging and spectroscopic studies of SN 1987A with {\it Chandra} reveal that X-ray emission of SN 1987A originates from the hot gas heated by interaction of the blast wave with the ring-like dense circumstellar medium (CSM) that was produced by the massive progenitor's equatorial stellar winds before the SN explosion. The blast wave is now sweeping through dense CSM all around the inner ring, and thus SN 1987A is rapidly brightening in soft X-rays. At the age of 20 yr (as of 2007 January), X-ray luminosity of SN 1987A is $L_{\rm X}$ $\sim$ 2.4 $\times$ 10$^{36}$ ergs s$^{-1}$ in the 0.5$-$10 keV band. X-ray emission is described by two-component plane shock model with electron temperatures of $kT$ $\sim$ 0.3 and 2 keV. As the shock front interacts with dense CSM all around the inner ring, the X-ray remnant is now expanding at a much slower rate of $v$ $\sim$ 1400 km s$^{-1}$ than it was until 2004 ($v$ $\sim$ 6000 km s$^{-1}$).
description: 8 pages, 4 figures (including 2 color figs), 3 tables. To appear in the proceedings of "Supernova 1987A: 20 Years after Supernovae and Gamma-Ray Bursters", held in Aspen CO. USA, Feb 19-23, 2007
Quasi-angular momentum of Bose and Fermi gases in rotating optical lattices
Creators: name: Peden, Brandon M.
name: Bhat, Rajiv
name: Krämer, Meret
name: Holland, Murray J.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: The notion of quasi-angular momentum is introduced to label the eigenstates of a Hamiltonian with a discrete rotational symmetry. This concept is recast in an operatorial form where the creation and annihilation operators of a Hubbard Hamiltonian carry units of quasi-angular momentum. Using this formalism, the ground states of ultracold gases of non-interacting fermions in rotating optical lattices are studied as a function of rotation, and transitions between states of different quasi-angular momentum are identified. In addition, previous results for strongly-interacting bosons are re-examined and compared to the results for non-interacting fermions. Quasi-angular momentum can be used to distinguish between these two cases. Finally, an experimentally accessible signature of quasi-angular momentum is identified in the momentum distributions of single-particle eigenstates.
description: Added references, fixed typos, expanded introduction. 22 pages, 12 figures, accepted for publication in J. Phys. B (publication date: Sep 7, 2007)
Classification of superpotentials
Creators: name: Dancer, Andrew
name: Wang, Mckenzie
Publisher: name: arXiv
Year: 2007
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53C25

description: We extend our previous classification of superpotentials of ``scalar curvature type" for the cohomogeneity one Ricci-flat equations. We now consider the case not covered in our previous paper, i.e., when some weight vector of the superpotential lies outside (a scaled translate of) the convex hull of the weight vectors associated with the scalar curvature function of the principal orbit. In this situation we show that either the isotropy representation has at most 3 irreducible summands or the first order subsystem associated to the superpotential is of the same form as the Calabi-Yau condition for submersion type metrics on complex line bundles over a Fano Kähler-Einstein product.
VP2-06: Magnetism and magnetic anisotropy of a single  rare-earth atom on transition metal dichalcogenides: A first-principles prediction
Creators: Batnyam Narangerel
Tumentsereg Ochirkhuyag
Odontuya Bayarsaikhan
Gonchigsuren Munkhsaikhan and Dorj Odkhuu
Publisher: name: IEEE
Year: 2023

Fundamental Properties and Cooperative Phenomena (Virtual)
Exploring magnetism in otherwise nonmagnetic two-dimensional materials, such as graphene and transition metal dichalcogenides (TMDs), is at the heart of spintronics research. Employing systematic density-functional theory and Monte Carlo simulations, we have studied the energetics and magnetism of a series of rare-earth (RE) atoms on WSe2 and MoSe2 monolayers with various possible natural defects. In this talk, we will emphasize on significantly large perpendicular magnetocrystalline anisotropy (PMA) up to an order of 10 meV predicted in WSe2 with Nd and Sm substitutions for the W site. Numerical results of PMA are elucidated in terms of an energy level change in the large spin-orbit coupled RE 4f – W 5d orbital states that are hybridized with the Se 4p orbital states in the low-spin bipyramidal crystal field. The present argument is also applicable for MoSe2. The RE concentration and strain dependences of magnetic moment and PMA, and its underlying mechanism will also be discussed. The research is funded by Office of Naval Research and Office of Naval Research Global of the US Department of Defense Grant N62909-23-1-2035.
FB-01: Spin Polarized Tunneling in​ Antiferromagnet/Insulator/Ferromagnet​ Tunnel Junctions
Creators: Chung-Tao Chou
Brooke C. McGoldrick
Thanh Nguyen
Supriya Ghosh
K. Andre Mkhoyan
Mingda Li
and Luqiao Liu
Publisher: name: IEEE
Year: 2023

Antiferromagnets: Non-collinear Spin Structures and Dynamics
Achieving a high tunneling magnetoresistance (TMR) in junctions with antiferromagnetic (AFM) electrodes has been an enthusiastically pursued goal in spintronics, with the prospect of employing AFMs as next-generation memory and spin logic devices. Traditionally, a finite TMR is believed to be forbidden in AFM tunnel junctions due to the translation-time reversal symmetry in most collinear AFMs. Recently a high TMR has been theoretically predicted in non-collinear AFM tunnel junctions [1] and verified experimentally [2, 3]. However, the underlying mechanism for the TMR and the relation between TMR and AFM ordering are still not fully understood, and the TMR ratios need to be further increased. The study of spin polarized tunneling from a ferromagnet (FM) to an AFM in asymmetric tunnel junctions is also lacking. In this work, we study Mn3Sn/MgO/CoFeB asymmetric tunnel junctions where AFM Mn3Sn and FM CoFeB serve as fixed layer and free layer, respectively. Large TMR ratios up to 49% are observed in these junctions and are comparable to that in conventional FM tunnel junctions. The large TMR suggests the effective spin polarization in non-collinear AFMs can be as large as that in FMs when proper tunneling barrier and counter electrode are selected. Furthermore, opposed to previous beliefs, the TMR cannot be toggled by reorienting the AFM ordering in the bulk Mn3Sn and remains stable under a few Tesla magnetic fields. We systematically demonstrate that this unexpected field resilience of TMR is because the interfacial region of AFM behaves differently from the bulk. The interface-bulk decoupling has not been shown in conventional FM tunnel junctions and is a unique feature of AFMs. The new physical mechanisms revealed by our results are critical for understanding spin polarized tunneling in AFM tunnel junctions and improving their performance, including increasing the TMR ratio and enhancing the field robustness.References: [1] J. Dong, X. Li, and G. Gurung, Phys. Rev. Lett. 128, 197201 (2022) [2] P. Qin, H. Yan, and X. Wang, Nature 613, 485–489 (2023) [3] X. Chen, T. Higo, and K. Tanaka, Nature 613, 490–495 (2023)
Additional file 2 of Barriers and enablers of implementation of alcohol guidelines with pregnant women: a cross-sectional survey among UK midwives
Creators: name: Smith, Lesley A.
name: Dyson, Judith
name: Watson, Julie
name: Schölin, Lisa
Publisher: name: figshare
Year: 2021
Subjects: subject: Medicine
subject: Cell Biology
subject: Pharmacology
subject: Biotechnology
subject: Sociology
subject: FOS: Sociology
subject: 111714 Mental Health
subject: FOS: Health sciences

description: Additional file 2: Table S1. Description of TDF domains in relation to the study.
title: Dynamic processes in Rydberg-atom-ion systems
Creators: name: Berngruber, Moritz
Publisher: name: Universität Stuttgart
Year: 2024
Subjects: subject: 530

description: In this thesis an ion microscope is used to study ion-Rydberg interactions in a cold quantum gas of rubidium atoms in real space. This allowed the observation of charged ultralong-range Rydberg molecules consisting of an ion and a Rydberg atom. The molecule is based on a charge-induced flipping dipole bond and shows a bond length of several micrometers. Due to the versatile nature of the ion microscope, the molecules could not only be studied by means of conventional spectroscopy and mass spectrometry, but could also be directly observed in real space images. Thus, the spatial alignment, caused by the laser polarization during the photoassociation, could be detected in situ. Furthermore, the response of the molecule to an external electric field was investigated, opening up the possibility to not only associate the molecule in an aligned, but also an orientated way. Owing to the exceptionally long bond length of these molecules, dynamical processes are slowed down drastically, which provides the possibility to observe the molecular vibrational motion directly. Finally, the onset of collision dynamics between an ion and a Rydberg atom in a purely attractive potential was analyzed. At sufficiently small distances, the charge-induced Stark shift leads to a large number of avoided crossings between an atomic Rydberg state and the adjacent hydrogenic manifold. These crossings open up additional fast collision channels whose population can be described by a Landau-Zener hopping process. For a certain energy regime this results in a counter-intuitive behavior, as initially slow particles predominantly occupy steep collision channels and therefore experience a drastic speed up in the collisional process.
Leitbilder für unsere Dörfer
Creators: name: Lütkemeier, Harald
Publisher: name: LANDTECHNIK
Year: 1998

description: Jede Gemeinde, jedes Dorf braucht Zielvorstellungen für die künftige Entwicklung. Die Diskussion um ein Leitbild ist Ausdruck einer aktiven Dorfgemeinschaft und dreht sich um Fragen wie: Welche Stärken sind auszubauen, welche Konflikte zu lösen, welches attraktive Profil können wir entwickeln? Auf diese Fragen muss jedes Dorf eigene Antworten finden. Nachfolgend werden einige Instrumentarien und Lösungsansätze zur Diskussion gestellt.
description: LANDTECHNIK, Bd. 53 Nr. 6 (1998)
Energiebilanzen von Raps bei unterschiedlichen Anbauintensitäten
Creators: name: Moerschner, Johannes
name: Gerowitt, Bärbel
Publisher: name: LANDTECHNIK
Year: 1998

description: Vorgestellt werden die energetischen Auswirkungen von vier beziehungsweise drei in ihrer Anbauintensität variierten Fruchtfolgen am Beispiel des Raps. Die achtjährigen Produktionsdaten stammen aus dem Göttinger INTEX-Projekt. Berücksichtigt wird sowohl direkter als auch indirekter Energieverbrauch. Im Ergebnis zeigt sich, dass sich die Systeme in ihrem Gesamtenergieverbrauch je ha deutlich unterscheiden (dieser sinkt mit zunehmender Extensivierung). Der Energieeinsatz je kg Ertrag war in den flexibel reduzierten Varianten am geringsten. Hinsichtlich einer vergleichbaren Vorgehensweise bei der Bilanzierung (verwendete Energieäquivalente, Systemgrenzen, Methodik) besteht Abstimmungsbedarf innerhalb des Ernährungssektors.
description: LANDTECHNIK, Bd. 53 Nr. 6 (1998)
Additional file 3 of Barriers and enablers of implementation of alcohol guidelines with pregnant women: a cross-sectional survey among UK midwives
Creators: name: Smith, Lesley A.
name: Dyson, Judith
name: Watson, Julie
name: Schölin, Lisa
Publisher: name: figshare
Year: 2021
Subjects: subject: Medicine
subject: Cell Biology
subject: Pharmacology
subject: Biotechnology
subject: Sociology
subject: FOS: Sociology
subject: 111714 Mental Health
subject: FOS: Health sciences

description: Additional file 3.
Mechanische Belastung beim Größensortieren von Speisezwiebeln
Creators: name: Oberbarnscheidt, Bernd
name: Herold, Bernd
Publisher: name: LANDTECHNIK
Year: 1998

description: Speisezwiebeln werden nach Größe sortiert. Die Sortierverfahren haben wesentlichen Anteil an den bei der Aufbereitung und Vermarktung verursachten mechanischen Belastungen. Dadurch sind Qualitätsminderungen der Speisezwiebeln bedingt. Um unnötige Qualitätsverluste zu vermeiden, sind das Sortierprinzip sowie die Einsatz und Betriebsbedingungen sorgfältig auszuwählen oder zu gestalten und ständig zu kontrollieren.
description: LANDTECHNIK, Bd. 53 Nr. 6 (1998)
Fall-Studien
Creators: name: Kleinknecht, Christoph
name: Müller, Joachim
name: Köller, Karlheinz
Publisher: name: LANDTECHNIK
Year: 1998

description: Praxisübliche Säschare legen die Körner in einem unterschiedlich großen Streubereich ab. Neben der Längsverteilung kann dies auch die Genauigkeit der Tiefenablage beeinflussen. Zur Untersuchung des Streubereiches verschiedener praxisüblicher Säschare und eines neuentwickelten Kaskadenschares wurden an der Universität Hohenheim Versuchsreihen durchgeführt. Mit Videoaufnahmen konnte der Streubereich visuell dargestellt werden. Eine genaue Quantifizierung der Ablagepositionen erfolgte durch den Einsatz eines Optosensors. Während das Kaskadenschar die Körner in einem Bereich bis zu 21 mm ablegt, kann die Streuung bei Normalscharen mehr als 150 mm erreichen.
description: LANDTECHNIK, Bd. 53 Nr. 6 (1998)
Additional file 1 of Identification of MFGE8 and KLK5/7 as mediators of breast tumorigenesis and resistance to COX-2 inhibition
Creators: name: Tian, Jun
name: Wang, Vivian
name: Wang, Ni
name: Baharak Khadang
name: Boudreault, Julien
name: Khldoun Bakdounes
name: Ali, Suhad
name: Lebrun, Jean-Jacques
Publisher: name: figshare
Year: 2021
Subjects: subject: Genetics
subject: FOS: Biological sciences

description: Additional file 1:. Figure S1. DEGs in COX-2-high patient and COX-2-low patient groups.
Additional file 2 of Identification of MFGE8 and KLK5/7 as mediators of breast tumorigenesis and resistance to COX-2 inhibition
Creators: name: Tian, Jun
name: Wang, Vivian
name: Wang, Ni
name: Baharak Khadang
name: Boudreault, Julien
name: Khldoun Bakdounes
name: Ali, Suhad
name: Lebrun, Jean-Jacques
Publisher: name: figshare
Year: 2021
Subjects: subject: Genetics
subject: FOS: Biological sciences

description: Additional file 2: Figure S2. a, Percentage of gene copy number amplification (orange) and mRNA upregulation (grey) of each of the 43 DEGs in metastatic breast cancer patient cohorts (n = 180). Genes to the left of the dashed lines were considered as highly amplified and expressed. b, mRNA expression levels of final selected 10 candidate genes in TNBC versus non-TNBC patients in a collection of breast cancer patient cohort from the Breast Cancer Gene-Expression Miner v4.0 online platform.
Additional file 3 of Identification of MFGE8 and KLK5/7 as mediators of breast tumorigenesis and resistance to COX-2 inhibition
Creators: name: Tian, Jun
name: Wang, Vivian
name: Wang, Ni
name: Baharak Khadang
name: Boudreault, Julien
name: Khldoun Bakdounes
name: Ali, Suhad
name: Lebrun, Jean-Jacques
Publisher: name: figshare
Year: 2021
Subjects: subject: Genetics
subject: FOS: Biological sciences

description: Additional file 3: Figure S3. Kaplan-Meier survival analysis showing the relationship between each of the candidate gene expression and overall survival as well as distant metastasis free survival rates in a collection of basal breast cancer patient cohorts (n = 241) from Kaplan-Meier plotter online platform.
Geostatistics applied to forecasting metal prices
Creators: name: Faulkner, Reginald Lloyd
Publisher: name: University of British Columbia
Year: 2010

description: The objective of this thesis was to investigate the effectiveness of kriging as a predictor of future prices for copper, lead and zinc on the London Metal Exchange. The annual average metal prices from 1884 to 1986 were deflated into constant price series with reference to a base of 1984 prices. Analysis of the data showed that the requirement of stationarity was satisfied if the price series were divided into three distinct time periods viz. 1884 to 1917; 1918 to 1953; 1954 to 1986. For copper each of the three time periods were studied in detail, but for lead and zinc only the most recent period was included in this thesis. Spherical models gave a good fit to the experimental semi-variograms computed for each metal-time period and were used to predict future prices by ordinary kriging. Universal Kriging was applied to the most recent time period for each metal by fitting a polynomial curve to the price-time series, computing experimental semi-variograms from the residuals and then fitting spherical models which were used to predict future prices. Within the most recent price-time series, a further subdivision was made by taking that portion of the period from the highest price to 1986. Experimental semi-variograms from the residuals from fitted polynomial curves showed pure nugget effect and consequently extrapolation of the polynomial was used as the price predictor. The kriged and extrapolated future price estimates were compared to future prices estimated by a simple random walk using residual sums of squared differences. For four of the five time series analyzed, ordinary kriging produced the best future price estimates. For copper from 1918 to 1953 , the simple random walk was marginally better than ordinary kriging. This was probably due to the low price variability in this period resulting from the Great Depression and government price controls associated with the Second World War and the Korean War. Specific forecasts for 1985 and 1986 were most accurate for copper and lead by universal kriging and most accurate for zinc by ordinary kriging. The results are encouraging and future investigations should include: applying other kriging methods : analyzing daily and monthly prices : comparing results with more sophisticated time series analysis techniques.
VP12-30: Synthesis of CoFe2O4/Mesoporous Carbon hybrid Nanocomposite with Enhanced Microwave Absorption in   K and Ka-band
Creators: Pooja Pantola
Sunil Kumar
Deepti Chaudhary
Pooja Agarwal & Bijoy Kumar Kuanr
Publisher: name: IEEE
Year: 2023

Sensors, High Frequency Devices, and Power Devices (Virtual)
With the rapid development of 5G signals, autonomous vehicles, wireless communications devices, the electromagnetic (EM) radiation resulted in several adverse effects on environment and human body [1]. To reduce EM radiation, microwave absorption materials can effectively be used. Conventional microwave absorbing materials generally comprised of magnetic loss materials and dielectric loss materials. Carbonaceous materials as microwave absorbers have been investigated because of their high dielectric loss and environmental stability. To improve absorption capability in a wide frequency range, nanocomposites of carbon materials with various with magnetic materials are in a great demand [2-3]. Herein, CoFe2O4/Mesoporous carbon nanocomposite was fabricated via a facile hydrothermal method and demonstrates their microwave absorption properties in K and Ka-band frequencies. XRD results confirmed the pure phase formation of CoFe2O4 sample. Vibrating sample magnetometer (VSM) shows (Fig.1) decrease of magnetization value for CoFe2O4/Mesoporous carbon nanocomposites that can be ascribed to the increasing contents of non-magnetic mesoporous carbon. The reflection loss (RL) results demonstrate that minimum RL reached to -31 dB with a matching thickness of 2.5 mm (Fig.2). Effective absorption bandwidth (EAB) obtained is 4.4 GHz The enhanced microwave absorption properties derive from the synergistic effect between dielectric loss of mesoporous carbon, magnetic loss of ferrite and better impendence matching at the interface. The dielectric loss can be associated to the polarization relaxation and mesoporous carbon conductivity. Magnetic loss arises from the natural resonance of ferrite materials. The reflection loss and EAB results shows that CoFe2O4/Mesoporous carbon nanocomposite shows the admirable microwave absorption performances and can be a promising candidate for Stealth technology and in advanced communication system.References: [1] L. Wang, Z. Du, L. Xiang, D. Hou, S. Zhu, J. Zhu, Y. Mai, R. Che, The ordered mesoporous carbon coated graphene as a high-performance broadband microwave absorbent, Carbon 179 (2021) 435-444. [2] Y. Liu, D. He, O. Dubrunfaut, A. Zhang, H. Zhang, L. Pichon, J. Bai, GO-CNTs hybrids reinforced epoxy composites with porous structure as microwave absorbers, Composites Science and Technology 200 (2020) 108450. [3] X. Zhang, L. Cai, Z. Xiang, W. Lu, Hollow CuS microflowers anchored porous carbon composites as lightweight and broadband microwave absorber with flame-retardant and thermal stealth functions, Carbon 184 (2021) 514-525.
Dynamic range of hypercubic stochastic excitable media
Creators: name: Assis, Vladimir R. V.
name: Copelli, Mauro
Publisher: name: arXiv
Year: 2007
Subjects: subject: Neurons and Cognition (q-bio.NC)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Cellular Automata and Lattice Gases (nlin.CG)
subject: Biological Physics (physics.bio-ph)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: We study the response properties of d-dimensional hypercubic excitable networks to a stochastic stimulus. Each site, modelled either by a three-state stochastic susceptible-infected-recovered-susceptible system or by the probabilistic Greenberg-Hastings cellular automaton, is continuously and independently stimulated by an external Poisson rate h. The response function (mean density of active sites rho versus h) is obtained via simulations (for d=1, 2, 3, 4) and mean field approximations at the single-site and pair levels (for all d). In any dimension, the dynamic range of the response function is maximized precisely at the nonequilibrium phase transition to self-sustained activity, in agreement with a reasoning recently proposed. Moreover, the maximum dynamic range attained at a given dimension d is a decreasing function of d.
description: 7 pages, 4 figures
Untersuchungen am Mähdrescherhäcksler
Creators: name: Kämmerer, Dirk
Publisher: name: LANDTECHNIK
Year: 1998

description: Der Strohhäcksler am Mähdrescher ist eine Standardausrüstung, die in vielen Ackerbaubetrieben bis zu 100 % der Einsatzzeit in Betrieb ist. An einem stationären Versuchsstand werden grundlegende Untersuchungen zum Förder- und Schneidvorgang im Mähdrescherhäcksler durchgeführt. Durch die Aufteilung der Antriebsleistung in verschiedene Einzelkomponenten wird eine genaue Analyse der Auswirkungen von Parametervariationen ermöglicht. Leistungsbestimmende Parameter können so optimiert und der spezifische Leistungsbedarf gesenkt werden.
description: LANDTECHNIK, Bd. 53 Nr. 6 (1998)
Unkrautregulierung mit Heißwasser im Obst und Weinbau
Creators: name: Kurfeß, Werner
Publisher: name: LANDTECHNIK
Year: 1998

description: Der langjährige Einsatz von Herbiziden im Obst und Weinbau muss aus ökologischer Sicht kritisch beurteilt werden. Die Nachfrage nach alternativen Verfahren, die hinsichtlich Wirkung und Wirtschaftlichkeit eine Alternative zum Herbizideinsatz darstellen könnten, nimmt zu. Eine Möglichkeit der herbizidfreien Unkrautregulierung des Baumstreifens ist die Behandlung mit einer Kombination aus Heißwasser und Heißgasen. Erste Freilandversuche im Jahr 1996 an der Universität Hohenheim zeigten, dass Arbeitsgeschwindigkeiten bis 6 km/h möglich sind. Im Rahmen eines Forschungsprojektes wurde daraufhin ein Laborprüfstand für Grundlagenuntersuchungen sowie ein verbesserter Prototyp für den Freilandeinsatz entwickelt. Die Prüfstandversuche zeigten mögliche Arbeitsgeschwindigkeiten bis 8 km/h.
description: LANDTECHNIK, Bd. 53 Nr. 6 (1998)