Search results for "Realization"

Spectral Properties of Partial *-Algebras

2010

We continue our study of topological partial *algebras focusing our attention to some basic spectral properties. The special case of partial *-algebras of operators is examined first, in order to find sufficient hints for the study of the abstract case. The outcome consists in the selection of a class of topological partial *-algebras (partial GC*-algebras) that behave well from the spectral point of view and that allow, under certain conditions, a faithful realization as a partial O*-algebra.

Optical d-level frequency-time-based cluster states

2019

Cluster states, a specific class of multi-partite entangled states, are of particular importance for quantum science, as such systems are equivalent to the realization of one-way (or measurement-based) quantum computers [1]. In this scheme, algorithms are implemented through high-fidelity measurements on the parties of the state [2]. While two-level (i.e. qubit) cluster states have been realized so far, increasing the number of particles to boost the computational resource comes at the price of significantly reduced coherence time and detection rates, as well as increased sensitivity to noise, restricting the realization of discrete cluster states to a record of eight qubits. In contrast, t…

Probing dynamics of dense suspensions: three-dimensional cross-correlation technique

1997

We describe the realization of a novel three-dimensional (3D) cross-correlation scheme, which provides the possibility to measure dynamic structure factors of highly concentrated colloidal samples without contributions of multiply scattered light. The apparatus is easier to align and more compact than the two-colour cross-correlation apparatus, which is commercially available. This should make the 3D cross-correlation set-up more convenient for routine applications, for example in industrial laboratories. We describe the set-up and discuss some special features of the optical components.

Determining a Random Schrödinger Operator : Both Potential and Source are Random

2020

We study an inverse scattering problem associated with a Schr\"odinger system where both the potential and source terms are random and unknown. The well-posedness of the forward scattering problem is first established in a proper sense. We then derive two unique recovery results in determining the rough strengths of the random source and the random potential, by using the corresponding far-field data. The first recovery result shows that a single realization of the passive scattering measurements uniquely recovers the rough strength of the random source. The second one shows that, by a single realization of the backscattering data, the rough strength of the random potential can be recovered…

2021

The bosonic analogs of topological insulators have been proposed in numerous theoretical works, but their experimental realization is still very rare, especially for spin systems. Recently, two-dim...

Many-particle dynamics of bosons and fermions in quasi-one-dimensional flat-band lattices

2013

The difference between boson and fermion dynamics in quasi-one-dimensional lattices is studied by calculating the persistent current in small quantum rings and by exact simulations of the time evolution of the many-particle state in two cases: expansion of a localized cloud and collisions in a Newton’s cradle. We consider three different lattices which in the tight-binding model exhibit flat bands. The physical realization is considered to be an optical lattice with bosonic or fermionic atoms. The atoms are assumed to interact with a repulsive short-range interaction. The different statistics of bosons and fermions lead to different dynamics. Spinless fermions are easily trapped in the flat…

Surface Acoustic Bloch Oscillations, the Wannier-Stark Ladder, and Landau-Zener Tunneling in a Solid

2010

We present the experimental observation of Bloch oscillations, the Wannier-Stark ladder, and Landau-Zener tunneling of surface acoustic waves in perturbed grating structures on a solid substrate. A model providing a quantitative description of our experimental observations, including multiple Landau-Zener transitions of the anticrossed surface acoustic Wannier-Stark states, is developed. The use of a planar geometry for the realization of the Bloch oscillations and Landau-Zener tunneling allows a direct access to the elastic field distribution. The vertical surface displacement has been measured by interferometry.

Measuring Spatiotemporal Dependencies in Bivariate Temporal Random Sets with Applications to Cell Biology

2008

Analyzing spatiotemporal dependencies between different types of events is highly relevant to many biological phenomena (e.g., signaling and trafficking), especially as advances in probes and microscopy have facilitated the imaging of dynamic processes in living cells. For many types of events, the segmented areas can overlap spatially and temporally, forming random clumps. In this paper, we model the binary image sequences of two different event types as a realization of a bivariate temporal random set and propose a nonparametric approach to quantify spatial and spatiotemporal interrelations using the pair correlation, cross-covariance, and the Ripley K functions. Based on these summary st…

Thermal Stability of a DC/DC Converter with Inductor in Partial Saturation

2021

Inductors operated in quasi saturation in dc–dc converters allow reduction of the core size and realization costs; on the other hand, they imply an increase of dissipated power that can jeopardize the thermal stability of the converter. In this article, this issue is studied by a mathematical model able to represent both the inductor nonlinearity and its temperature dependence. The main losses, such as ohmic, skin effect and magnetic, are taken into account in the model. The inductor is characterized by a polynomial curve whose parameters are a function of the temperature. Finally, the whole converter is modeled and simulation results, obtained on a boost converter, are compared with experi…

Architectures “on ruins” and ambiguous transparency: the glass in preservation and communication of archaeology

2008

Abstract The contemporary architecture is characterized by an even more marked transparency, as a result of a continuous experimentation all directed towards the search of the built “lightness”, that is towards the “dematerialization” of the architecture and the consequent loss of weight connected to the excess of form. It is in 1851 that a New Architectural Age springs because of the realization of the Crystal Palace, in London – that has addressed towards the experimentation of the glass as an architectural, structural element and of design. Today, part of this experimentation has been applied for some interventions of coverage, protection and communication in situ of the archaeological r…