Search results for "Planar"
showing 10 items of 412 documents
Field propagator of a dressed junction: Fluorescence lifetime calculations in a confined geometry
1997
The study of the fluorescence phenomenon by near-field optical techniques requires one to describe precisely the spontaneous emission change occurring when the fluorescing particle is placed in a complex optical environment. For this purpose, the field susceptibility (also called the field propagator) of a planar junction formed by a cavity bounded by two semi-infinite bodies with arbitrary optical constant is derived within the framework of linear-response theory. The field propagator associated with the junction is then modified in a self-consistent manner to account for the presence of any arbitrary object inside the junction. As a first illustration the alteration of the fluorescence li…
Resetting of a planar superconducting quantum memory
2009
We consider and analyze a scheme for the reset of a M × N planar array of inductively coupled Josephson flux qubits. We prove that it is possible to minimize the resetting time of an arbitrary chosen row of qubits by properly switching on and off the coupling between pairs of qubits belonging to the same column. In addition, the analysis of the time evolution of the array allows us to single out the class of generalized W states which can be successfully reset.
Four-phase patterns in a forced nonlinear optical oscillator
2009
We present preliminary theoretical and experimental results indicating that a high Fresnel number nonlinear optical oscillator with planar mirrors can display four-phase multistability, eventually leading to four-phase patterns. Such situation is similar to that emerging in extended oscillatory systems forced within a 4:1 resonance and, to the best of our knowledge, has not been predicted nor observed previously in an optical system.
The planar double box integral for top pair production with a closed top loop to all orders in the dimensional regularisation parameter
2018
We compute systematically for the planar double box Feynman integral relevant to top pair production with a closed top loop the Laurent expansion in the dimensional regularisation parameter $\varepsilon$. This is done by transforming the system of differential equations for this integral and all its sub-topologies to a form linear in $\varepsilon$, where the $\varepsilon^0$-part is strictly lower triangular. This system is easily solved order by order in the dimensional regularisation parameter $\varepsilon$. This is an example of an elliptic multi-scale integral involving several elliptic sub-topologies. Our methods are applicable to similar problems.
Development of an Endcap DIRC for PANDA
2014
Abstract The aim of this research is to develop a planar DIRC detector showing advantages and performance similar to a classical, barrel shaped DIRC, but at smaller polar angles which cannot be accessed using a cylindrical geometry. The device will complement the PANDA Barrel DIRC by covering polar angles from 5° to 22°. The envisaged π /K-separation is ≥ 3 σ up to 4 GeV/c. A major challenge is the adaption of the device to the PANDA environment including a magnetic field of ~1–2 T, high rates and radiation, limited space for optics and sensors as well as the lack of a common first-level trigger. This paper discusses a detector design which forms a compromise between these constraints and a…
High-precision studies of domain-wall properties in the 2D Gaussian Ising spin glass
2019
In two dimensions, short-range spin glasses order only at zero temperature, where efficient combinatorial optimization techniques can be used to study these systems with high precision. The use of large system sizes and high statistics in disorder averages allows for reliable finite-size extrapolations to the thermodynamic limit. Here, we use a recently introduced mapping of the Ising spin-glass ground-state problem to a minimum-weight perfect matching problem on a sparse auxiliary graph to study square-lattice samples of up to 10 000 × 10 000 spins. We propose a windowing technique that allows to extend this method, that is formally restricted to planar graphs, to the case of systems with …
Observation of Centrality-Dependent Acoplanarity for Muon Pairs Produced via Two-Photon Scattering in Pb+Pb Collisions at sNN=5.02 TeV with the ATLA…
2018
This Letter presents a measurement of γγ→μ^{+}μ^{-} production in Pb+Pb collisions recorded by the ATLAS detector at the Large Hadron Collider at sqrt[s_{NN}]=5.02 TeV with an integrated luminosity of 0.49 nb^{-1}. The azimuthal angle and transverse momentum correlations between the muons are measured as a function of collision centrality. The muon pairs are produced from γγ through the interaction of the large electromagnetic fields of the nuclei. The contribution from background sources of muon pairs is removed using a template fit method. In peripheral collisions, the muons exhibit a strong back-to-back correlation consistent with previous measurements of muon pair production in ultrap…
Efficient Pole Expansion of the Generalized Impedance Matrix Representation for Planar Waveguide Junctions
2006
This paper proposes a novel pole expansion of the generalized impedance matrix representation for planar waveguide junctions. Proceeding in this way, we have obtained a very efficient algorithm for the accurate wide-band modelling of such junctions, since the most expensive computations are performed outside the frequency loop. For verification purposes, several practical examples are shown in order to prove the numerical efficiency and accuracy provided by this new technique.
Conductivity reconstructions using real data from a new planar electrical impedance tomography device
2013
Abstract In this paper, we present results of reconstructions using real data from a new planar electrical impedance tomography device developed at the Institut fur Physik, Johannes Gutenberg Universitat, Mainz, Germany. The prototype consists of a planar sensing head of circular geometry, and it was designed mainly for breast cancer detection. There are 12 large outer electrodes arranged on a ring of radius cm where the external currents are injected, and a set of 54 point-like high-impedance inner electrodes where the induced voltages are measured. Two direct (i.e. non-iterative) reconstruction algorithms are considered: one is based on a discrete resistor model, and the other one is an …
Applications of wavelets to quantum mechanics: A pedagogical example
1995
We discuss in many details two quantum mechanical models of planar electrons which are very much related to the Fractional Quantum Hall Effect. In particular, we discuss the localization properties of the trial ground states of the models starting from considerations on the numerical results on the energy. We conclude that wavelet theory can be conveniently used in the description of the system. Finally we suggest applications of our results to the Fractional Quantum Hall Effect.