7,087 research outputs found
Statistical properties of spectral fluctuations for a quantum system with infinitely many components
Extending the idea formulated in Makino {\it{et al}}[Phys.Rev.E
{\bf{67}},066205], that is based on the Berry--Robnik approach [M.V. Berry and
M. Robnik, J. Phys. A {\bf{17}}, 2413], we investigate the statistical
properties of a two-point spectral correlation for a classically integrable
quantum system. The eigenenergy sequence of this system is regarded as a
superposition of infinitely many independent components in the semiclassical
limit. We derive the level number variance (LNV) in the limit of infinitely
many components and discuss its deviations from Poisson statistics. The slope
of the limiting LNV is found to be larger than that of Poisson statistics when
the individual components have a certain accumulation. This property agrees
with the result from the semiclassical periodic-orbit theory that is applied to
a system with degenerate torus actions[D. Biswas, M.Azam,and S.V.Lawande, Phys.
Rev. A {\bf 43}, 5694].Comment: 6 figures, 10 page
Simplicity of eigenvalues in the Anderson model
We give a simple, transparent, and intuitive proof that all eigenvalues of
the Anderson model in the region of localization are simple
Defining Early Positive Response to Psychotherapy: An Empirical Comparison Between Clinically Significant Change Criteria and Growth Mixture Modeling
Several different approaches have been applied to identify early positive change in response to psychotherapy so as to predict later treatment outcome and length as well as use this information for outcome monitoring and treatment planning. In this study, simple methods based on clinically significant change criteria and computationally demanding growth mixture modeling (GMM) are compared with regard to their overlap and uniqueness as well as their characteristics in terms of initial impairment, therapy outcome, and treatment length. The GMM approach identified a highly specific subgroup of early improving patients. These patients were characterized by higher average intake impairments and higher pre- to-posttreatment score differences. Although being more specific for the prediction of treatment success, GMM was much less sensitive than clinically significant and reliable change criteria. There were no differences between the groups with regard to treatment length. Because each of the approaches had specific advantages, results suggest a combination of both methods for practical use in routine outcome monitoring and treatment planning
String effects in Polyakov loop correlators
We compare the predictions of the effective string description of confinement
in finite temperature gauge theories to high precision Monte Carlo data for the
three-dimensional Z(2) gauge theory. We show that string interaction effects
become more relevant as the temperature is increased towards the deconfinement
one, and are well modeled by a Nambu-Goto string action.Comment: Lattice2002(nonzerot
Decorrelation estimates for the eigenlevels of the discrete Anderson model in the localized regime
The purpose of the present work is to establish decorrelation estimates for
the locally renormalized eigenvalues of the discrete Anderson model near two
distinct energies inside the localization region. In dimension one, we prove
these estimates at all energies. In higher dimensions, the energies are
required to be sufficiently far apart from each other
Theory of multiwave mixing and decoherence control in qubit array system
We develop a theory to analyze the decoherence effect in a charged qubit
array system with photon echo signals in the multiwave mixing configuration. We
present how the decoherence suppression effect by the {\it bang-bang} control
with the pulses can be demonstrated in laboratory by using a bulk
ensemble of exciton qubits and optical pulses whose pulse area is even smaller
than . Analysis is made on the time-integated multiwave mixing signals
diffracted into certain phase matching directions from a bulk ensemble.
Depending on the pulse interval conditions, the cross over from the decoherence
acceleration regime to the decoherence suppression regime, which is a peculiar
feature of the coherent interaction between a qubit and the reservoir bosons,
may be observed in the time-integated multiwave mixing signals in the realistic
case including inhomogeneous broadening effect. Our analysis will successfully
be applied to precise estimation of the reservoir parameters from experimental
data of the direction resolved signal intensities obtained in the multiwave
mixing technique.Comment: 19 pages, 11 figure
First Supramolecular Sensors for Phosphonate Anions
Fluorescent tripodal anion sensors with a 1,3,5-triethylbenzene core display a turn-on fluorescence response to phosphonate and phosphate anions and may be used as optical sensors. The properties of the receptors and sensors as well as their anion binding behavior were investigated both in solution and in solid state. The turn-on fluorescence response can be leveraged in sensing of phosphate anions and, most importantly, hydrolysis products of the nerve gas sarin, isopropyl methylphosphonate (IMP), and methylphosphonate (MP). The fluorescence signal amplification in the presence of anions allows for application of these molecules in a sensor microarray suitable for high-throughput screening.NSF CHE 0750303, EXP-LA 0731153BGSU (TIE Grant)Chemistr
- …