9,543 research outputs found
Distance between exact and approximate distributions of partial maxima under power normalization
We obtain the distance between the exact and approximate distributions of
partial maxima of a random sample under power normalization. It is observed
that the Hellinger distance and variational distance between the exact and
approximate distributions of partial maxima under power normalization is the
same as the corresponding distances under linear normalization.Comment: Published at http://dx.doi.org/10.15559/15-VMSTA42 in the Modern
Stochastics: Theory and Applications (https://www.i-journals.org/vtxpp/VMSTA)
by VTeX (http://www.vtex.lt/
Visualisation of an entangled channel spin-1 system
Co-variance matrix formalism gives powerful entanglement criteria for
continuous as well as finite dimensional systems. We use this formalism to
study a mixed channel spin-1 system which is well known in nuclear reactions. A
spin-j state can be visualized as being made up of 2j spinors which are
represented by a constellation of 2j points on a Bloch sphere using Majorana
construction. We extend this formalism to visualize an entangled mixed spin-1
system.Comment: 4 pages,4 figure
SU(2) Invariants of Symmetric Qubit States
Density matrix for N-qubit symmetric state or spin-j state (j = N/2) is
expressed in terms of the well known Fano statistical tensor parameters.
Employing the multiaxial representation [1], wherein a spin-j density matrix is
shown to be characterized by j(2j+1) axes and 2j real scalars, we enumerate the
number of invariants constructed out of these axes and scalars. These
invariants are explicitly calculated in the particular case of pure as well as
mixed spin-1 state.Comment: 7 pages, 1 fi
Spin Squeezing of Superposition of Biaxial State and two qubit Bell State
In this study we investigate the spin squeezing in superposition of a Biaxial
state [1,2] and Bell state. Numerical and analytical solutions for the length
of mean spin, mean spin direction and spin squeezing are given. It is shown
that both the mean spin direction and spin squeezing parameter are determined
by the coefficients of superposition and the relative phase.Comment: Int. J. Theor. Phys. (2013
Photodisintegration of aligned deuterons at astrophysical energies using linearly polarized photons
Following the model independent approach to deuteron photodisintegration with
linearly polarized rays, we show that the measurements of the tensor
analyzing powers on aligned deuterons along with the differential cross section
involve five different linear combinations of the isovector
amplitudes interfering with the isoscalar and amplitudes. This is
of current interest in view of the recent experimental finding
\cite{blackston1} that the three amplitudes are distinct and also the
reported experimental observation \cite{sawatzky} on the front-back (polar
angle) asymmetry in the differential cross section.Comment: 12 page
Squeezing of a coupled state of two spinors
The notion of spin squeezing involves reduction in the uncertainty of a
component of the spin vector below a certain limit. This aspect has been
studied earlier for pure and mixed states of definite spin. In this paper, this
study has been extended to coupled spin states which do not possess sharp spin
value. A general squeezing criterion has been obtained by requiring that a
direct product state for two spinors is not squeezed. The squeezing aspect of
entangled states is studied in relation to their spin- spin correlations.Comment: Typeset in LaTeX 2e using the style iopart, packages
iopams,times,amssymb,graphicx; 17 pages, 5 eps figure file
Squeezing in Multivariate Spin Systems
In contrast to the canonically conjugate variates , representing the
position and momentum of a particle in the phase space distributions, the three
Cartesian components, ,, of a spin- system constitute
the mutually non-commuting variates in the quasi-probabilistic spin
distributions. It can be shown that a univariate spin distribution is never
squeezed and one needs to look into either bivariate or trivariate
distributions for signatures of squeezing. Several such distributions result if
one considers different characteristic functions or moments based on various
correspondence rules. As an example, discrete probability distribution for an
arbitrary spin-1 assembly is constructed using Wigner-Weyl and Margenau-Hill
correspondence rules. It is also shown that a trivariate spin-1 assembly
resulting from the exposure of nucleus with non-zero quadrupole moment to
combined electric quadrupole field and dipole magnetic field exhibits squeezing
in cerain cases.Comment: 13 pages, 1 Table, Presented at ICSSUR-05, Franc
Microrheological Studies of Regenerated Silk Fibroin Solution by Video Microscopy
We have carried out studies on the rheological properties of regenerated silk
fibroin (RSF) solution using video microscopy. The degummed silk from the
Bombyx mori silkworm was used to prepare RSF solution by dissolving it in
calcium nitrate tetrahydrate-methanol solvent. Measurements were carried out by
tracking the position of an embedded micron-sized polystyrene bead within the
RSF solution through video imaging. The time dependent mean squared
displacement (MSD) of the bead in solution and hence, the complex shear modulus
of this solution was calculated from the bead's position information. An
optical tweezer was used to transport and locate the bead at any desired site
within the micro-volume of the sample, to facilitate the subsequent free-bead
video analysis. We present here the results of rheological measurements of the
silk polymer network in solution over a frequency range, whose upper limit is
the frame capture rate of our camera, at full resolution. By examining the
distribution of MSD of beads at different locations within the sample volume,
we demonstrate that this probe technique enables us to detect local
inhomogeneties at micrometer length scales, not detectable either by a
rheometer or from diffusing wave spectroscopy.Comment: 5 page
Crystal structure of 3-benzoyl-2-[(5-bromo-2-Hydroxy-3-methoxybenzylidene)amino]-4,5,6,7-tetrahydrobenzo[b]thiophene
In the cyclohexene ring of the title compound, C23H20BrNO3S, the -(CH2)4- atoms are positionally disordered [occupancy ratio = 0.753 (6):0.247 (6)]. The ring has a half-chair conformation for both the major and minor components. The dihedral angles between the mean plane of the thiophene ring and those of the benzene and phenyl rings are 35.2 (4) and 57.7 (3)°, respectively. The planes of the two aryl rings are twisted with respect to each other by 86.4 (6)°. In the molecule, there is an O-H...N hydrogen bond forming an S(6) ring motif. In the crystal, molecules are linked via C-H...O hydrogen bonds, forming chains parallel to [100].Publisher PDFPeer reviewe
Entangling capabilities of Symmetric two qubit gates
Our work addresses the problem of generating maximally entangled two spin-1/2
(qubit) symmetric states using NMR, NQR, Lipkin-Meshkov-Glick Hamiltonians.
Time evolution of such Hamiltonians provides various logic gates which can be
used for quantum processing tasks. Pairs of spin-1/2's have modeled a wide
range of problems in physics. Here we are interested in two spin-1/2 symmetric
states which belong to a subspace spanned by the angular momentum basis {|j =
1, {\mu}>; {\mu} = +1, 0,-1}. Our technique relies on the decomposition of a
Hamiltonian in terms of SU(3) generators. In this context, we define a set of
linearly independent, traceless, Hermitian operators which provides an
alternate set of SU(n) generators. These matrices are constructed out of
angular momentum operators Jx,Jy,Jz. We construct and study the properties of
perfect entanglers acting on a symmetric subspace i.e., spin-1 operators that
can generate maximally entangled states from some suitably chosen initial
separable states in terms of their entangling power.Comment: 12 page
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