148 research outputs found
Nonclassicality of photon-added-then-subtracted and photon-subtracted-then-added states
We formulate the density matrices of a quantum state obtained by first adding
multi-photons to and then subtracting multi-photons from any arbitrary state as
well as performing the same process in the reverse order. Considering the field
to be initially in a thermal (or in an even coherent) state, we evaluate the
photon number distribution, Wigner function and Mandel's parameter of the
resulting field. We show graphically that in which order multi-photons are
added and subtracted has a noticeable effect on the temporal behavior of these
statistical properties.Comment: 9 pages, 7 figure
Realistic continuous-variable quantum teleportation using a displaced Fock state channel
We investigate ideal and non-ideal continuous-variable quantum teleportation
protocols realized by using an entangled displaced Fock state resource. The
characteristic function formulation is applied to measure the relative
performance of displaced Fock state for teleporting squeezed and coherent
states. It is found that for such single-mode input fields, the average
fidelity remains at the classical threshold, suggesting that the displaced Fock
states are not advantageous for teleportation. We also discuss the major
decoherence effects, caused by the inaccuracy in Bell measurements and photon
losses for the propagation of optical fields via fibre channels. The changes in
the teleportation fidelity are described by adjusting the gain factor (),
reflectivity (), mode damping (), and the number of thermal photons
(). The possibility of successful teleportation can be optimized
by fixing these realistic parameters.Comment: 16 pages, 9 figure
Lower-vs-Higher Order Non-classicality of Photon-added Bell-type Entangled Coherent States
We compare the lower and higher order non-classicality of a class of the
photon-added Bell-type entangled coherent states (PBECS) got from Bell-type
entangled coherent states using creation operators. We obtained lower and
higher order criteria namely Mandel's , antibunching ,
Subpoissioning photon statistics and Squeezing for the states
obtained. Further we observe that first three criteria does not gives
non-classicality for any state and higher order criteria gives very high
positive values for all values of parameters. Also the fourth or last criterion
gives non-classicality for lower order as well as higher order.Comment: published in conference proceeding
Detecting nonclassicality and non-Gaussianity of a coherent superposed quantum state
In this paper, we investigate the nonclassicality and non-Gaussianity of a
coherent superposed quantum state (CSQS) which is obtained by applying a
coherent superposition of field annihilation () and creation ()
operators, to a classical coherent state ,
where and are scalars with . Such an operation, when applied
on states having classical characters, introduces strong nonclassicality. We
use different criteria to check the nonclassicality and non-Gaussianity of the
considered quantum state. We first compute the Wigner function of CSQS. To
study the nonclassicality of the considered state we further use (i) linear
entropy (LE) (ii) Wigner logarithmic negativity (WLN) and (iii) skew
information based measure. Relative entropy based measure is considered to
analyze the variation in non-Gaussianity of CSQS. Finally, the dynamics of the
Wigner function evolving under the photon loss channel is addressed to probe
the effect of noise on nonclassicality as well as non-Gaussianity of CSQS.Comment: 9 pages, 7 figures. arXiv admin note: text overlap with
arXiv:2109.12145 by other author
General expansion of natural power of linear combination of Bosonic operators in normal order
In quantum mechanics, bosonic operators are mathematical objects that are
used to represent the creation () and annihilation () of bosonic
particles. The natural power of a linear combination of bosonic operators
represents an operator with as the exponent and
are the variables free from bosonic operators. The normal ordering of
these operators is a mathematical technique that arranges the operators so that
all the creation operators are to the left of the annihilation operators,
reducing the number of terms in the expression. In this paper, we present a
general expansion of the natural power of a linear combination of bosonic
operators in normal order. We show that the expansion can be expressed in terms
of binomial coefficients and the product of the normal-ordered operators using
the direct method and than prove it using the fundamental principle of
mathematical induction. We also derive a formula for the coefficients of the
expansion in terms of the number of bosons and the commutation relation between
the creation and annihilation operators. Our results have important
applications in the study of many-body systems in quantum mechanics, such as in
the calculation of correlation functions and the evaluation of the partition
function. The general expansion presented in this paper provides a powerful
tool for analyzing and understanding the behavior of bosonic systems, and can
be applied to a wide range of physical problems.Comment: submitted in conference proceeding
Lower- versus higher-order nonclassicalities for a coherent superposed quantum state
A coherent state is defined conventionally in different ways such as a
displaced vacuum state, an eigenket of annihilation operator or as an infinite
dimensional Poissonian superposition of Fock states. In this work, we describe
a superposition of field annihilation and creation operators
acting on a continuous variable coherent state and specify
it by . We analyze the lower- as well as the higher-order
nonclassical properties of . The comparison is performed by using
a set of nonclassicality witnesses (e.g., higher-order photon-statistics,
higher-order antibunching, higher-order sub-Poissonian statistics, higher-order
squeezing, Agarwal-Tara parameter, Klyshko's condition and a relatively new
concept, matrix of phase-space distribution). It is found that higher-order
criteria are much more efficient to detect the presence of nonclassicality as
compared to lower-order conditions.Comment: 10 pages, 10 figure
Consumeras Acceptance towards Genetically Modified Crops and Growth of the Economy: A Theoretical Approach
This paper develops a three-sector theoretical growth model to capture the role of consumers acceptance towards the second generation of genetically modified GM crops in the long run growth process of the economy An Acceptance towards GM crop parameter is defined as a ratio of consumption of GM to traditional variety of food whose growth rate is determined by growth rate of human capital Dynamic stability of the system is ensured provided the value of acceptance parameter is within a certain range A range of the acceptance parameter is also obtained which ensures not only the dynamic stability of the system but also ensures higher rate of growth of an economy that produces both GM and non-GM crops compared to an economy that does not produce GM crops The empirical validation of the model through panel data analysis suggests that research and development activity in agriculture is key to the growth process of the economy as it helps to form acceptance towards new technology among consumer
Dynamics of an atom cavity field system in interacting Fock space
In this paper, we investigate one-time passing of a -type three-level atom
through a single-mode interacting field in a cavity. We extend the idea of
elementary Jaynes-Cummings model by assuming that the field vector belongs to
interacting Fock space. In the process, we arrive at a state vector which will
be analyzed to study the nonclassicality of the evolved state of the system.Comment: 14 pages, 5 figure
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