2,116 research outputs found
Correlation dynamics of dipolar bosons in 1D triple well optical lattice
We study the correlation dynamics triggered by lattice depth quench in a
system of three dipolar bosons in 1D triple well optical lattice from the first
principle using the multiconfigurational time-dependent Hartree method for
bosons (MCTDHB). The comparison with contact interaction is also presented. For
forward quench , system exhibits the collapse-revival dynamics
in the time evolution of normalized first-order Glauber's correlation function
both for the contact as well as for the dipolar interaction which is
reminiscent of the one observed in Greiner's experiment [Nature, {\bf 415}
(2002)]. We define the collapse and revival time ratio as the figure of merit
() which can uniquely distinguish the timescale of dynamics for dipolar
interaction from that of contact interaction. In the reverse quench process
, the superfluid state is never achieved for dipolar
interaction. The long-range repulsive tail, in the dipolar interaction,
inhibits the spread of correlation across the lattice sites. For contact
interaction the collapse-revival dynamics is again set-up with a different
timescale.Comment: 8 pages, 4 color figure
Enhancing Human Aspect of Software Engineering using Bayesian Classifier
IT industries in current scenario have to struggle effectively in terms of
cost, quality, service or innovation for their subsistence in the global
market. Due to the swift transformation of technology, software industries owe
to manage a large set of data having precious information hidden. Data mining
technique enables one to effectively cope with this hidden information where it
can be applied to code optimization, fault prediction and other domains which
modulates the success nature of software projects. Additionally, the efficiency
of the product developed further depends upon the quality of the project
personnel. The position of the paper therefore is to explore potentials of
project personnel in terms of their competency and skill set and its influence
on quality of project. The above mentioned objective is accomplished using a
Bayesian classifier in order to capture the pattern of human performance. By
this means, the hidden and valuable knowledge discovered in the related
databases will be summarized in the statistical structure. This mode of
predictive study enables the project managers to reduce the failure ratio to a
significant level and improve the performance of the project using the right
choice of project personnel.Comment: 5 Pages, 2 Figures. arXiv admin note: substantial text overlap with
arXiv:1104.4163, arXiv:1201.3418 by other author
Fisher information in confined hydrogen-like ions
Fisher information (I) is investigated for confined hydrogen atom (CHA)-like
systems in conjugate and spaces. A comparative study between CHA and
free H atom (with respect to ) is pursued. In many aspects, inferences in
CHA are significantly different from free counterpart; that includes its
dependence on . The role of atomic number and atomic radius is
discussed. Further, a detailed systematic result of with respect to
variation of confinement radius is presented, with particular emphasis on
\emph{non-zero}- states. Several new interesting observations are
recorded. Most of these results are of benchmark quality and presented for the
first time
Information entropy and complexity measure in generalized Kratzer potential
Shannon entropy (), Fisher information () and a measure equivalent to
Fisher-Shannon complexity of a ro-vibrational state of diatomic
molecules (O, O, NO, NO) with generalized Kratzer potential is
analyzed.
\emph{Exact} analytical expression of I_{\rvec} is derived for the
arbitrary state, whereas the same could be done for I_{\pvec} with
state. It is found that shifting from neutral to the cationic
system, I_{\rvec} increases while S_{\rvec} decreases, consistent with the
interpretation of a localization in the probability distribution. Additionally,
this study reveals that increases with the number of nodes in a
system
Transformation and summation formulas for Kampe de Feriet series.
The double hypergeometric Kamp\'e de F\'eriet series
depends upon 9 complex parameters. We present three cases with 2 relations
between those 9 parameters, and show that under these circumstances
can be written as a series. Some limiting
cases of these transformation formulas give rise to new summation results for
special 's. The actual transformation results arose out of
the study of 9- coefficients
A perturbative renormalization group approach to driven quantum systems
We use a perturbative momentum shell renormalization group (RG) approach to
study the properties of a driven quantum system at zero temperature. To
illustrate the technique, we consider a bosonic theory with an
arbitrary time dependent interaction parameter , where is the drive frequency and derive the RG equations for
the system using a Keldysh diagrammatic technique. We show that the scaling of
is analogous to that of temperature for a system in thermal
equilibrium and its presence provides a cutoff scale for the RG flow. We
analyze the resultant RG equations, derive an analytical condition for such a
drive to take the system out of the gaussian regime, and show that the onset of
the non-gaussian regime occurs concomitantly with appearance of
non-perturbative mode coupling terms in the effective action of the system. We
supplement the above-mentioned results by obtaining them from equations of
motions of the bosons and discuss their significance for systems near critical
points described by time-dependent Landau-Ginzburg theories.Comment: v2 11pages 7 figs; minor changes from v
Various complexity measures in confined hydrogen atom
Several well-known statistical measures similar to \emph{LMC} and
\emph{Fisher-Shannon} complexity have been computed for confined hydrogen atom
in both position () and momentum () spaces. Further, a more generalized
form of these quantities with R\'enyi entropy () is explored here. The role
of scaling parameter in the exponential part is also pursued. is evaluated
taking order of entropic moments as in
and spaces. Detailed systematic results of these measures with respect to
variation of confinement radius is presented for low-lying states such
as, - and . For \emph{nodal} states, such as and ,
as progresses there appears a maximum followed by a minimum in space,
having certain values of the scaling parameter. However, the corresponding
-space results lack such distinct patterns. This study reveals many other
interesting features.Comment: 15 pages, 4 tables, 4 figure
Data Mining for Prediction of Human Performance Capability in the Software-Industry
The recruitment of new personnel is one of the most essential business
processes which affect the quality of human capital within any company. It is
highly essential for the companies to ensure the recruitment of right talent to
maintain a competitive edge over the others in the market. However IT companies
often face a problem while recruiting new people for their ongoing projects due
to lack of a proper framework that defines a criteria for the selection
process. In this paper we aim to develop a framework that would allow any
project manager to take the right decision for selecting new talent by
correlating performance parameters with the other domain-specific attributes of
the candidates. Also, another important motivation behind this project is to
check the validity of the selection procedure often followed by various big
companies in both public and private sectors which focus only on academic
scores, GPA/grades of students from colleges and other academic backgrounds. We
test if such a decision will produce optimal results in the industry or is
there a need for change that offers a more holistic approach to recruitment of
new talent in the software companies. The scope of this work extends beyond the
IT domain and a similar procedure can be adopted to develop a recruitment
framework in other fields as well. Data-mining techniques provide useful
information from the historical projects depending on which the hiring-manager
can make decisions for recruiting high-quality workforce. This study aims to
bridge this hiatus by developing a data-mining framework based on an
ensemble-learning technique to refocus on the criteria for personnel selection.
The results from this research clearly demonstrated that there is a need to
refocus on the selection-criteria for quality objectives.Comment: Data Mining for Prediction of Human Performance Capability in the
Software-Industry, International Journal of Data-Mining and Knowledge
Management Process (IJDKP) - March 2015 Issu
Optical Lattice Modulation Spectroscopy for Spin-orbit Coupled Bosons
Interacting bosons with two "spin'' states in a lattice show novel
superfluid-insulator phase transitions in the presence of spin-orbit coupling.
Depending on the parameter regime, bosons in the superfluid phase can condense
to either a zero momentum state or to one or multiple states with finite
momentum, leading to an unconventional superfluid phase. We study the response
of such a system to modulation of the optical lattice potential. We show that
the change in momentum distribution after lattice modulation shows distinct
patterns in the Mott and the superfluid phase and these patterns can be used to
detect these phases and the quantum phase transition between them. Further, the
momentum resolved optical modulation spectroscopy can identify both the gapless
(Goldstone) gapped amplitude (Higgs) mode of the superfluid phase and clearly
distinguish between the superfluid phases with a zero momentum condensate and a
twisted superfluid phase by looking at the location of these modes in the
Brillouin zone. We discuss experiments which can test our theory.Comment: v2, 9 figs 14 pages (minor changes and added figs
Excited states of molecules in strong uniform and non-uniform magnetic fields
This paper reports an implementation of Hartree-Fock linear response with
complex orbitals for computing electronic spectra of molecules in a strong
external magnetic fields. The implementation is completely general, allowing
for spin-restricted, spin-unrestricted, and general two-component reference
states. The method is applied to small molecules placed in strong uniform and
non-uniform magnetic fields of astrochemical importance at the Random Phase
Approximation level of theory. For uniform fields, where comparison is
possible, the spectra are found to be qualitatively similar to those recently
obtained with equation of motion coupled cluster theory. We also study the
behaviour of spin-forbidden excitations with progressive loss of spin symmetry
induced by non-uniform magnetic fields. Finally, the equivalence of length and
velocity gauges for oscillator strengths when using complex orbitals is
investigated and found to hold numerically
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