Miracle-dz/UniFAR-FTUs huggingface dataset:
Surface-electrode ion traps for scalable quantum computing

The major challenges in trapped-ion quantum computation are to scale up few-ion experiments to many qubits and to improve control techniques so that quantum logic gates can be carried out with higher fidelities. This thesis reports experimental progress in both of these areas. In the early part of the thesis we describe the fabrication of a surface-electrode ion trap, the development of the apparatus and techniques required to operate it and the successful trapping of 40 Ca + ions. Notably we developed methods to control the orientation of the principal axes and to minimise ion micromotion. We propose a repumping scheme that simplifies heating rate measurements for ions with low-lying D levels, and use it to characterise the electric field noise in the trap. Surface-electrode traps are important because they offer a route to dense integration of electronic and optical control elements using existing microfabrication technology. We explore this scaling route by testing a series of three traps that were microfabricated at Sandia National Laboratories. Investigations of micromotion and charging of the surface by laser beams were carried out and improvements to future traps are suggested. Using one of these traps we also investigated anomalous electrical noise from the electrode surfaces and discovered that it can be reduced by cleaning with a pulsed laser. A factor of two decrease was observed; this represents the first in situ removal of this noise source, an important step towards higher gate fidelities. In the second half of the thesis we describe the design and construction of an experiment for the purpose of replacing laser-driven multi-qubit quantum logic gates with microwave-driven ones. We investigate magnetic-field-independent hyperfine qubits in 40 Ca + as suitable qubits for this scheme. We make a design study of how best to integrate an ion trap with the microwave conductors required to implement the gate and propose a novel integrated resonant structure. The trap was fabricated and ions were successfully loaded. Single-qubit experiments show that the microwave fields above the trap are in excellent agreement with software simulations. There are good prospects for demonstrating a multi-qubit gate in the near future. We conclude by discussing the possibilities for larger-scale quantum computation by combining microfabricated traps and microwave control.
The Next 700 Challenge Problems for Reasoning with Higher-Order Abstract Syntax Representations: Part 1-A Common Infrastructure for Benchmarks

A variety of logical frameworks support the use of higher-order abstract syntax (HOAS) in representing formal systems. Although these systems seem superficially the same, they differ in a variety of ways; for example, how they handle a context of assumptions and which theorems about a given formal system can be concisely expressed and proved. Our contributions in this paper are three-fold: 1) we develop a common infrastructure for representing benchmarks for systems supporting reasoning with binders, 2) we present several concrete benchmarks, which highlight a variety of different aspects of reasoning within a context of assumptions, and 3) we design an open repository ORBI, (Open challenge problem Repository for systems supporting reasoning with BInders). Our work sets the stage for providing a basis for qualitative comparison of different systems. This allows us to review and survey the state of the art, which we do in great detail for four systems in Part 2 of this paper (Felty et al, 2015). It also allows us to outline future fundamental research questions regarding the design and implementation of meta-reasoning systems.
LETTER TO THE EDITOR: Scalar field collapse in three-dimensional AdS spacetime

We describe the results of a numerical calculation of circularly symmetric scalar field collapse in three spacetime dimensions with a negative cosmological constant. The procedure uses a double null formulation of the Einstein-scalar equations. We see evidence of black hole formation on first implosion of a scalar pulse if the initial pulse amplitude A is greater than a critical value A*. Sufficiently near criticality the apparent horizon radius rAH grows with pulse amplitude according to the formula rAH~(A-A*)0.81.
Relativistic MOND theory based on the Khronon scalar field

We investigate a model of modified gravity recovering the modified Newtonian dynamics (MOND) in the non-relativistic limit, based on the introduction of a preferred time foliation violating Lorentz invariance in the weak-field regime. Lorentz-invariance violation has been studied in the framework of Einstein-aether theory, the generalization of which, known as non-canonical Einstein-aether theory, having been proposed as a relativistic formulation of MOND. Our model can be seen as a minimal specialization to the hypersurface orthogonal case, which allows a different interpretation in terms of the preferred time : it can be either treated as a dynamical scalar field in a 4D formulation, or chosen as the time coordinate in a 3+1 formulation. We discuss the equivalence of the two points of view and the non-relativistic limit of the model.
Anisotropy probe of galactic and extra-galactic dark matter annihilations

We study the flux and the angular power spectrum of gamma rays produced by dark matter (DM) annihilations in the Milky Way (MW) and in extra-galactic halos. The annihilation signal receives contributions from: (a) the smooth MW halo, (b) resolved and unresolved substructures in the MW, (c) external DM halos at all redshifts, including (d) their substructures. Adopting a self-consistent description of local and extra-galactic substructures, we compute the angular power spectrum of gamma-ray anisotropies and show that, quite independently from the prescription used for the concentration parameters c(M,z), an interesting signature of DM annihilations could soon be discovered by the Fermi LAT satellite at low multipoles, l{approx}100, assuming a particle physics scenario that does not violate gamma-ray constraints from the Galactic center. The DM contribution to the angular power spectrum is dominated by MW substructures (with mass M{>=}10{sup 4}M{sub {center_dot}}), while, at least for the substructures' models that we have adopted, the contribution of extra-galactic annihilations is negligible at all scales. MW subhalos also dominate the annihilation flux in the majority of the sky, with the smooth galactic halo being brighter only in the very central region.
Rotating white dwarf models with finite-temperature envelope

We present new numerical method to compute structures of differentially rotating white dwarfs with thermal stratification. Our models have cores composed of ions and completely degenerate electrons and have isentropic envelopes composed of ions, photons, partially degenerate electrons and positrons. The models are intended to mimic very early phases of remnants of white dwarf binary mergers, some of which may lead to type Ia supernovae. The effect of hot envelope to increase the mass depends on its chemical composition through the mean molecular weight of the envelope. For uniformly rotating models, we see only a small increase in mass even in the presence of hot envelope. Differential rotation changes it drastically and super-Chandrasekhar mass model whose mass doubles the Chandrasekhar mass of the degenerate star for some parameter choices. We also compute quasi-equilibrium evolutionary sequences of remnants by fixing either total angular momentum or entropy in the envelope. Existence of these sequences depends on various factors such as the remnant mass, the profile of differential rotation, the entropy and the chemical composition of the envelope.
Dressing the chopped-random-basis optimization: A bandwidth-limited access to the trap-free landscape

In quantum optimal control theory the success of an optimization algorithm is highly influenced by how the figure of merit to be optimized behaves as a function of the control field, i.e. by the control landscape. Constraints on the control field introduce local minima in the landscape --false traps-- which might prevent an efficient solution of the optimal control problem. Rabitz et al. [Science 303, 1998 (2004)] showed that local minima occur only rarely for unconstrained optimization. Here, we extend this result to the case of bandwidth-limited control pulses showing that in this case one can eliminate the false traps arising from the constraint. Based on this theoretical understanding, we modify the Chopped Random Basis (CRAB) optimal control algorithm and show that this development exploits the advantages of both (unconstrained) gradient algorithms and of truncated basis methods, allowing to always follow the gradient of the unconstrained landscape by bandwidth-limited control functions. We study the effects of additional constraints and show that for reasonable constraints the convergence properties are still maintained. Finally, we numerically show that this approach saturates the theoretical bound on the minimal bandwidth of the control needed to optimally drive the system.
Application of frequency domain processing to X-ray radiographic images of welding defects

X-ray radiographic technique is widely used as Nondestructive Testing (NDT) for inspection of welding joints. The quality of X-ray images is frequently sensitive for noise, lighting and working place surroundings. Therefore, such images need to be carefully examined to identify welding discontinuities. However, the human interpretative are usually contradictory and may cause confusion. Present work has proposed an image processing technique based on frequency domain processing to clarify the X-ray radiographic images taken for different welding discontinuities. The images are captured using low-resolution video camera and high-resolution digital camera. Preprocessing imaging tasks are performed to reduce the noise in the low- resolution video sequence images. Subsequently, low-pass followed by emphasis high-pass frequency filters are applied to enhance the images with appropriate cut-off frequencies. It is found that high-frequency domain image filtering is enhancing the morphological features of the X-ray images. The enhanced images become visually cleared and the welding discontinuities are possibility accessible.
The Knotty Question of the Jet of PKS B1421–490

We report the discovery of unusually strong optical and X-ray emission associated with a knot in the radio jet of PKS B1421-490. The knot is the brightest feature observed beyond the radio band, with knot/core flux ratios ~300 and 3.7 at optical and X-ray frequencies, respectively. We interpret the extreme optical output of the knot as synchrotron emission. The nature of the X-ray emission is unclear. We consider a second synchrotron component, inverse Compton emission from a relativistic, decelerating jet, and the possibility that this feature is a chance superposition of an unusual BL Lac object.
Search for hadronic transition $\chi_{cJ}\to\eta_{c}\pi^{+}\pi^{-}$ and observation of $\chi_{cJ}\to K\bar{K}\pi\pi\pi$

Hadronic transitions of $\chi_{cJ}\to \eta_{c}\pi^{+}\pi^{-}$ (J=0, 1, 2) are searched for using a sample of $1.06\times 10^{8}$ $\psi(3686)$ events collected with the BESIII detector at the BEPCII storage ring. The $\etac$ is reconstructed with $K_{S}^{0}K^{+}\pi^{-}+c.c. $ and $K^{+}K^{-}\pi^{0}$ final states. No signals are observed in any of the three $\chi_{cJ}$ states in either $\etac$ decay mode. At the 90% confidence level, the upper limits are determined to be $\BR(\chi_{c0}\to \eta_{c}\pi^{+}\pi^{-})<0.07%$, $\BR(\chi_{c1}\to \eta_{c}\pi^{+}\pi^{-})<0.32%$, and $\BR(\chi_{c2}\to \eta_{c}\pi^{+}\pi^{-})<0.54%$. The upper limit of $\BR(\chi_{c1}\to \eta_{c}\pi^{+}\pi^{-}$ is lower than the existing theoretical prediction by almost an order of magnitude. The branching fractions of $\chi_{cJ}\to K_{S}^{0}K^{+}\pi^{-}\pi^{+}\pi^{-}+c.c.$, $K^{+}K^{-}\pi^{+}\pi^{-}\pi^{0}$, $\omega K^{+}K^{-}$ and $\phi\pi^{+}\pi^{-}\pi^{0}$ (J=0, 1, 2) are measured for the first time.
Very-high-energy gamma-ray observations of the Type Ia Supernova SN 2014J with the MAGIC telescopes

Context. In this work we present data from observations with the MAGIC telescopes of SN 2014J detected on January 21 2014, the closest Type Ia supernova since Imaging Air Cherenkov Telescopes started to operate. Aims. We aim to probe the possibility of very-high-energy (VHE; E >= 100 GeV) gamma rays produced in the early stages of Type Ia supernova explosions. Methods. We performed follow-up observations after this supernova (SN) explosion for five days, between January 27 and February 2 2014. We searched for gamma-ray signals in the energy range between 100 GeV and several TeV from the location of SN 2014J using data from a total of similar to 5.5 h of observations. Prospects for observing gamma rays of hadronic origin from SN 2014J in the near future are also being addressed. Results. No significant excess was detected from the direction of SN 2014J. Upper limits at 95% confidence level on the integral flux, assuming a power-law spectrum, dF/dE proportional to E-Gamma, with a spectral index of Gamma = 2.6, for energies higher than 300 GeV and 700 GeV, are established at 1.3 x 10(-12) and 4.1 x 10-(13) photons cm(-2) s(-1), respectively. Conclusions. For the first time, upper limits on the VHE emission of a Type Ia supernova are established. The energy fraction isotropically emitted into TeV gamma rays during the first similar to 10 days after the supernova explosion for energies greater than 300 GeV is limited to 10(-6) of the total available energy budget (similar to 10(51) erg). Within the assumed theoretical scenario, the MAGIC upper limits on the VHE emission suggest that SN 2014J will not be detectable in the future by any current or planned generation of Imaging Atmospheric Cherenkov Telescopes.
DISCOVERY OF VERY HIGH ENERGY GAMMA-RAY RADIATION FROM THE BL LAC 1ES 0806+524

The high-frequency-peaked BL Lacertae object 1ES 0806+524, at redshift z = 0.138, was observed in the very high energy (VHE) gamma-ray regime by VERITAS between 2006 November and 2008 April. These data encompass the two- and three-telescope commissioning phases, as well as observations with the full four-telescope array. 1ES 0806+524 is detected with a statistical significance of 6.3 standard deviations from 245 excess events. Little or no measurable variability on monthly timescales is found. The photon spectrum for the period 2007 November to 2008 April can be characterized by a power law with photon index 3.6 ± 1.0stat ± 0.3sys between ∼ 300 GeV and ∼ 700 GeV. The integral flux above 300 GeV is (2.2 ± 0.5stat ± 0.4sys) × 10−12 cm−2 s−1 which corresponds to 1.8% of the Crab Nebula flux. Non-contemporaneous multiwavelength observations are combined with the VHE data to produce a broadband spectral energy distribution that can be reasonably described using a synchrotron--self-Compton model.
Lattice symmetries and regular magnetic orders in classical frustrated antiferromagnets

We consider some classical and frustrated lattice spin models with global O(3) spin symmetry. No general analytical method to find a ground state exists when the spin dependence of the Hamiltonian is more than quadratic (i.e., beyond the Heisenberg model) and/or when the lattice has more than one site per unit cell. To deal with these cases, we introduce a family of variational spin configurations, dubbed “regular magnetic orders” (RMO’s), which respect all the lattice symmetries modulo global O(3) spin transformations (rotations and/or spin flips). The construction of these states is made explicit through a group-theoretical approach, and all the RMO’s on the square, triangular, honeycomb, and kagome lattices are listed. Their equal-time structure factors and powder averages are shown for comparison with experiments. Well known Neel states with one, two, or three sublattices on various lattices are RMO’s, but the RMO’s also encompass exotic nonplanar states with cubic, tetrahedral, or cuboctahedral geometry of the T=0 order parameter. Regardless of the details of the Hamiltonian (with the same symmetry group), a large fraction of these RMO’s are energetically stationary with respect to small deviations of the spins. In fact, these RMO’s appear as exact ground states in large domains of parameter space of simple models that we have considered. As examples, we display the variational phase diagrams of the J1-J2-J3 Heisenberg model on all the previous lattices as well as that of the J1-J2-K ring-exchange model on square and triangular lattices.
La fluctuation en genre grammatical des substantifs inanimés en vieil-anglais

The existence of nouns of variable genre in Old English was brought to the linguistic community’s attention at the end of the 19th century. Despite the rather high number of nouns assigned to several genders in dictionaries dealing with Old English, to date there has been no substantial study of the phenomenon. This thesis is a usage-based study that explores the notion of nouns of variable gender by distinguishing them from other types of gender-variation in Old English texts. It also explores in detail the factors behind various grammatical gender assignments.It departs from the notion of agreement and its expression in gender-sensitive markers. A corpus of a hundred and fourteen nouns assigned to several genders in the dictionaries – seventy-eight native and thirty-six borrowed from Latin and Old Norse – are analysed in context in order to identify the various factors that influence the lexicographers’ decision-making. Some important developments in the usage of the formerly gender-sensitive markers in the discourse might have influenced the latter to a certain degree. Or, they might be a reflection of variability as an internal feature of the nouns analysed. This study deals with the notion of variation as a cover-term for disagreement, which reflects the discontinuity of the link between a controller and its agreement targets, and, on the other hand, for variability, maintaining the agreement on the cognitive level and allowing the transition from one gender to the other depending on the choice of the speaker.
Observational evidence for thin AGN disks

Observational evidence for thin AGN disks include their spectrum and spectral features, polarization, inclination and X‐ray line and continuum reflection features.These are discussed, in a critical way, in an attempt to find the ones that are the least model dependent. The optical and ultraviolet continuum of AGNs can be explainedin various different ways, one of which is thermal emission by geometrically thin accretion disks. The continuum emission of such disks is not yet understood well enough to clearly distinguish this from other continuum emitting processes. This is also the case for several spectral features, including absorption and emission edges, proposed to be clear disk‐emission signatures. The sign and the strength of such edges are model dependent and relativistic broadening and shifting makes them hard to detect. Polarization observations at ultraviolet wavelengths, are more promising. In particular, the presence or absence of the predicted Lyman edge polarization feature may be used as a d.
Study of Early Universe in an M Theoretic Model

In this thesis we study early universe in the frame work of M theory. In particular We assume that the early universe is homogeneous, anisotropic, and is dominated by the mutually BPS 22'55' intersecting branes of M theory. We find that, asymptotically, three spatial directions expand to infinity and the remaining spatial directions reach stabilised values. We give a physical description of the stabilisation mechanism.
Photoionization modelling of planetary nebulae — II. Galactic bulge nebulae, a comparison with literature results

We have constructed photoionization models of five galactic bulge planetary nebulae using our automatic method, which enables a fully self-consistent determination of the physical parameters of a planetary nebula. The models are constrained using the spectrum, the IRAS and radio fluxes and the angular diameter of the nebula. We also conducted a literature search for physical parameters determined with classical methods for these nebulae. Comparison of the distance-independent physical parameters with published data shows that the stellar temperatures generally are in good agreement and can be considered reliable. The literature data for the electron temperature, electron density and also for the abundances show a large spread, indicating that the use of line diagnostics is not reliable and that the accuracy of these methods needs to be improved. Comparison of the various abundance determinations indicates that the uncertainty in the electron temperature is the main source of uncertainty in the abundance determination. The stellar magnitudes predicted by the photoionization models are in good agreement with observed values.
Toward the minimal realization of a light composite Higgs

Work in progress is reported on a particularly interesting gauge theory with a fermion doublet in the two-index symmetric (sextet) representation of the SU(3) color gauge group. Extending previous studies we outline our strategy as we investigate Goldstone dynamics and Electroweak scale setting from chiral symmetry breaking ($\chi$ SB), test the GMOR relation from the spectrum of the Dirac operator and the related chiral condensate, begin to develop and test mixed action based improved analysis of $\chi$ SB with new run plans at fixed topology to cross over from the p-regime to the epsilon-regime of $\chi$ SB, continue to pursue the light $0^{++}$ scalar and its relation to the dilaton, and probe the scale-dependent running coupling from the perturbative UV scale to the scale of chiral symmetry breaking. Our observations suggest that the model is very close to the conformal window and a light composite scalar, perhaps the Higgs impostor with or without dilaton-like interpretation, appears to emerge with $0^{++}$ quantum numbers. The lightest baryon of the model on the 3 TeV scale has intriguing implications.
Repetitiveness in binary recurrences.

Let u be a function from the sei Z of rational integers to the set C of complex numbers satisfying the relation (1) u(« + 2) = Mu(n 41) Nu(n), n e Z, where Af, 7V Φ 0 are given complex numbers. Such a function is called a binary recurrence of complex numbers and we shall write u(n) = un. Let a be an arbitrary, but fixed, complex number. We are interested in the solubility of the equation (2) um = aun, m,neZ. Let ^(u, 0) = {(w, n) e Z x Z | m>n and um = aun}, and let r (u, a) = cardinality of $? (u, a). We shall show that except for certain obvious degenerate cases r (u, a) is bounded by a function which depends only on u and a. Unfortunately the bound produced by our proof is extremely large ; consequently no attempt is made to state the bound explicitly. The proof involves two cases : u (1) when all the ratios — are algebraic over 0, and "m (2) when some ratio is transcendental over 0. In the first case we show there is an effectively computable constant 5(u, a), which depends on both u and a, such that if (m, n) e ^(u, a) then \m\,\n\ ^5(u, a). The constant J? (u, a) is clearly dependent on both u and a. It is obtained using estimates that derive from A. Baker's estimates on linear forms of logarithms of algebraic numbers. It is our dependence on these estimates that restrict us to consider only binary recurrences. -