1,321 research outputs found
A Note on 1-Edge Balance Index Set
A graph labeling is an assignment of integers to the vertices or edges or both, subject to certain conditions. Varieties of graph labeling have been investigated by many authors [2], [3] [5] and they serve as useful models for broad range of applications
Enhancement of Geometric Phase by Frustration of Decoherence: A Parrondo like Effect
Geometric phase plays an important role in evolution of pure or mixed quantum
states. However, when a system undergoes decoherence the development of
geometric phase may be inhibited. Here, we show that when a quantum system
interacts with two competing environments there can be enhancement of geometric
phase. This effect is akin to Parrondo like effect on the geometric phase which
results from quantum frustration of decoherence. Our result suggests that the
mechanism of two competing decoherence can be useful in fault-tolerant
holonomic quantum computation.Comment: 5 pages, 3 figures, Published versio
On pseudo-hyperk\"ahler prepotentials
An explicit surjection from a set of (locally defined) unconstrained
holomorphic functions on a certain submanifold of (Sp_1(C) \times C^{4n}) onto
the set HK_{p,q} of local isometry classes of real analytic
pseudo-hyperk\"ahler metrics of signature (4p,4q) in dimension 4n is
constructed. The holomorphic functions, called prepotentials, are analogues of
K\"ahler potentials for K\"ahler metrics and provide a complete
parameterisation of HK_{p,q}. In particular, there exists a bijection between
HK_{p,q} and the set of equivalence classes of prepotentials. This affords the
explicit construction of pseudo-hyperk\"ahler metrics from specified
prepotentials. The construction generalises one due to Galperin, Ivanov,
Ogievetsky and Sokatchev. Their work is given a coordinate-free formulation and
complete, self-contained proofs are provided. An appendix provides a vital tool
for this construction: a reformulation of real analytic G-structures in terms
of holomorphic frame fields on complex manifolds.Comment: 53 pages; v2: minor amendments to Def.4.1 and Theorem 4.5; a
paragraph inserted in the proof of the latter; V3: minor changes; V4: minor
changes/ typos corrected for journal versio
Generic quantum walk using a coin-embedded shift operator
The study of quantum walk processes has been widely divided into two standard
variants, the discrete-time quantum walk (DTQW) and the continuous-time quantum
walk (CTQW). The connection between the two variants has been established by
considering the limiting value of the coin operation parameter in the DTQW, and
the coin degree of freedom was shown to be unnecessary [26]. But the coin
degree of freedom is an additional resource which can be exploited to control
the dynamics of the QW process. In this paper we present a generic quantum walk
model using a quantum coin-embedded unitary shift operation . The
standard version of the DTQW and the CTQW can be conveniently retrieved from
this generic model, retaining the features of the coin degree of freedom in
both variants.Comment: 5 pages, 1 figure, Publishe
Disordered quantum walk-induced localization of a Bose-Einstein condensate
We present an approach to induce localization of a Bose-Einstein condensate
in a one-dimensional lattice under the influence of unitary quantum walk
evolution using disordered quantum coin operation. We introduce a discrete-time
quantum walk model in which the interference effect is modified to diffuse or
strongly localize the probability distribution of the particle by assigning a
different set of coin parameters picked randomly for each step of the walk,
respectively. Spatial localization of the particle/state is explained by
comparing the variance of the probability distribution of the quantum walk in
position space using disordered coin operation to that of the walk using an
identical coin operation for each step. Due to the high degree of control over
quantum coin operation and most of the system parameters, ultracold atoms in an
optical lattice offer opportunities to implement a disordered quantum walk that
is unitary and induces localization. Here we present a scheme to use a
Bose-Einstein condensate that can be evolved to the superposition of its
internal states in an optical lattice and control the dynamics of atoms to
observe localization. This approach can be adopted to any other physical system
in which controlled disordered quantum walk can be implemented.Comment: 6 pages, 4 figures, published versio
Optimizing the discrete time quantum walk using a SU(2) coin
We present a generalized version of the discrete time quantum walk, using the
SU(2) operation as the quantum coin. By varying the coin parameters, the
quantum walk can be optimized for maximum variance subject to the functional
form and the probability distribution in the position
space can be biased. We also discuss the variation in measurement entropy with
the variation of the parameters in the SU(2) coin. Exploiting this we show how
quantum walk can be optimized for improving mixing time in an -cycle and for
quantum walk search.Comment: 6 pages, 6 figure
Quantumness of noisy quantum walks: a comparison between measurement-induced disturbance and quantum discord
Noisy quantum walks are studied from the perspective of comparing their
quantumness as defined by two popular measures, measurement-induced disturbance
(MID) and quantum discord (QD). While the former has an operational definition,
unlike the latter, it also tends to overestimate non-classicality because of a
lack of optimization over local measurements. Applied to quantum walks, we find
that MID, while acting as a loose upper bound on QD, still tends to reflect
correctly the trends in the behavior of the latter. However, there are regimes
where its behavior is not indicative of non-classicality: in particular, we
find an instance where MID increases with the application of noise, where we
expect a reduction of quantumness.Comment: 5 pages with 4 figures, Published Versio
Generation of hyperentangled states and two-dimensional quantum walks using - ()- plates and polarization beamsplitters
A single photon can be made to entangle simultaneously in its different
internal degrees of freedom (DoF) -- polarization, orbital angular momentum
(OAM), and frequency -- as well as in its external DoF -- path. Such
entanglement in multiple DoF is known as hyperentanglement and provide
additional advantage for quantum information processing. We propose a passive
optical setup using -plates and polarization beamsplitters to hyperentangle
an incoming single photon in polarization, OAM, and path DoF. By mapping
polarization DoF to a two-dimensional coin state, and path and OAM DoF to two
spatial dimensions, and , we present a scheme for realization of
two-dimensional discrete-time quantum walk using only polarization
beamsplitters and -plates ensuing the generation of hyperentangled states.
The amount of hyperentanglement generated is quantified by measuring the
entanglement negativity between any two DoF. We further show the
hyperentanglement generation can be controlled by using an additional coin
operation or by replacing the -plate with a -plate.Comment: A new appendix has been included, where Jones matrices are realized
using -plates and variable waveplate
Decoherence on a two-dimensional quantum walk using four- and two-state particle
We study the decoherence effects originating from state flipping and
depolarization for two-dimensional discrete-time quantum walks using four-state
and two-state particles. By quantifying the quantum correlations between the
particle and position degree of freedom and between the two spatial ()
degrees of freedom using measurement induced disturbance (MID), we show that
the two schemes using a two-state particle are more robust against decoherence
than the Grover walk, which uses a four-state particle. We also show that the
symmetries which hold for two-state quantum walks breakdown for the Grover
walk, adding to the various other advantages of using two-state particles over
four-state particles.Comment: 12 pages, 16 figures, In Press, J. Phys. A: Math. Theor. (2013
Assessing an Information Systems Master\u27s Curriculum Program: Revisiting the ACM\u27s MSIS 2006 Model Curriculum
The field of Information systems continues to change dynamically with the painful impact for reacting to those changes felt by both undergraduate and masters’ level programs. The purpose of this paper is to report the results of a comparative selfstudy of one MSIS program as a measure to assess its competitiveness among a set of other comparable, competitive and aspirant masters’ programs. The focus of the study is determine the viability of one specific master’s curriculum used currently to prepare students for professional careers in information systems in order to meet the marketplace challenges created by the ever-evolving information systems business needs. The fundamental methodology used in this study is based on that which was employed in a previous study conducted to assess the ‘fit’ of 86 MSIS programs with the MSIS 2000 Model Curriculum (Vijayaraman, et.al.) Findings will be presented that reflect shared learning objectives, curriculum content, currency, and relevancy necessary to assess whether changes to the current curriculum are necessary to establish a more competitive position among the three categories of comparable, competitive and aspirant university MSIS programs. One benefit that resulted from this initiative is the recognition that there has been relatively little research directed at assessing the overall direction of current MSIS programs and the need to revisit the need for a new MSIS model curriculum. The last endorsed MSIS model curriculum was published in 2006 (Gorgone, et.al. 2006), almost 10 years ago. It is the hope of presenting the results of this study that a discussion can begin to address the challenge of maintaining a viable MSIS curriculum that meets the current and future demands of the business communit
- …