Orthogonal-state-based protocols of quantum key agreement

Two orthogonal-state-based protocols of quantum key agreement (QKA) are proposed. The first protocol of QKA proposed here is designed for two-party QKA, whereas the second protocol is designed for multi-party QKA. Security of these orthogonal-state-based protocols arise from monogamy of entanglement. This is in contrast to the existing protocols of QKA where security arises from the use of non-orthogonal state (non-commutativity principle). Further, it is shown that all the quantum systems that are useful for implementation of quantum dialogue and most of the protocols of secure direct quantum communication can be modified to implement protocols of QKA.Comment: 9 pages, no figur

Higher order nonclassicalities of finite dimensional coherent states: A comparative study

Conventional coherent states (CSs) are defined in various ways. For example, CS is defined as an infinite Poissonian expansion in Fock states, as displaced vacuum state, or as an eigenket of annihilation operator. In the infinite dimensional Hilbert space, these definitions are equivalent. However, these definitions are not equivalent for the finite dimensional systems. In this work, we present a comparative description of the lower- and higher-order nonclassical properties of the finite dimensional CSs which are also referred to as qudit CSs (QCSs). For the comparison, nonclassical properties of two types of QCSs are used: (i) nonlinear QCS produced by applying a truncated displacement operator on the vacuum and (ii) linear QCS produced by the Poissonian expansion in Fock states of the CS truncated at (d-1)-photon Fock state. The comparison is performed using a set of nonclassicality witnesses (e.g., higher order antiubunching, higher order sub-Poissonian statistics, higher order squeezing, Agarwal-Tara parameter, Klyshko's criterion) and a set of quantitative measures of nonclassicality (e.g., negativity potential, concurrence potential and anticlassicality). The higher order nonclassicality witness have found to reveal the existence of higher order nonclassical properties of QCS for the first time.Comment: A comparative description of the higher-order nonclassical properties of the finite dimensional coherent state

The Relevant Operators for the Hubbard Hamiltonian with a magnetic field term

The Hubbard Hamiltonian and its variants/generalizations continue to dominate the theoretical modelling of important problems such as high temperature superconductivity. In this note we identify the set of relevant operators for the Hubbard Hamiltonian with a magnetic field term.Comment: 19 pages, RevTe

Quantum phase properties of photon added and subtracted displaced Fock states

Quantum phase properties of photon added and subtracted displaced Fock states (and a set of quantum states which can be obtained as the limiting cases of these states) are investigated from a number of perspectives, and it is shown that the quantum phase properties are dependent on the quantum state engineering operations performed. Specifically, the analytic expressions for quantum phase distributions and angular $Q$ distribution as well as measures of quantum phase fluctuation and phase dispersion are obtained. The uniform phase distribution of the initial Fock states is observed to be transformed by the unitary operation (i.e., displacement operator) into non-Gaussian shape, except for the initial vacuum state. It is observed that the phase distribution is symmetric with respect to the phase of the displacement parameter and becomes progressively narrower as its amplitude increases. The non-unitary (photon addition/subtraction) operations make it even narrower in contrast to the Fock parameter, which leads to broadness. The photon subtraction is observed to be a more powerful quantum state engineering tool in comparison to the photon addition. Further, one of the quantum phase fluctuation parameters is found to reveal the existence of antibunching in both the engineered quantum states under consideration. Finally, the relevance of the engineered quantum states in the quantum phase estimation is also discussed, and photon added displaced Fock state is shown to be preferable for the task.Comment: Quantum phase properties of an engineered quantum state has been studied from various perspective

Lower- and higher-order nonclassical properties of photon added and subtracted displaced Fock states

Nonclassical properties of photon added and subtracted displaced Fock states have been studied using various witnesses of lower- and higher-order nonclassicality. Compact analytic expressions are obtained for the nonclassicality witnesses. Using those expressions, it is established that these states and the states that can be obtained as their limiting cases (except coherent states) are highly nonclassical as they show the existence of lower- and higher-order antibunching and sub-Poissonian photon statistics, in addition to the nonclassical features revealed through the Mandel $Q_M$ parameter, zeros of Q function, Klyshko's criterion, and Agarwal-Tara criterion. Further, some comparison between the nonclassicality of photon added and subtracted displaced Fock states have been performed using witnesses of nonclassicality. This has established that between the two types of non-Gaussianity inducing operations (i.e., photon addition and subtraction) used here, photon addition influences the nonclassical properties more strongly. Further, optical designs for the generation of photon added and subtracted displaced Fock states from squeezed vacuum state have also been proposed.Comment: A comparative study of the nonclassicality present in photon added and subtracted displaced Fock states shows photon addition is generally preferable nonclassicality inducing operation, while subtraction also has advantage in some cases over additio

Higher-order nonclassical properties of a shifted symmetric cat state and a one-dimensional continuous superposition of coherent states

Role of quantum interference in the origin of higher-order nonclassical characteristics of radiation field has been probed vis-a-vis a discrete and a continuous superposition of coherent states. Specifically, the possibilities of observing higher-order nonclassical properties (e.g., higher-order antibunching (HOA), higher-order sub-Poissonian photon statistics (HOSPS), higher-order squeezing (HOS) of Hong-Mandel type and Hillery type) have been investigated using a shifted symmetric cat state that reduces to Yurke-Stoler, even and odd coherent states at various limits. This shifted symmetric cat state which can be viewed as a discrete superposition of coherent states is found to show HOA and HOSPS. Similarly, higher-order nonclassical properties of a one-dimensional continuous superposition of coherent states is also studied here. The investigation has revealed the existence of HOS and HOSPS in the one-dimensional continuous superposition of coherent states studied here. Effect of non-Gaussianity inducing operations (e.g., photon addition and addition followed by subtraction) on these superposition states have also been investigated. Finally, some comparisons have been made between the higher-order nonclassical properties of discrete and continuous superposition of coherent states

The Nature of Difficulties in Learning English by the students at Secondary School level in Pakistan

This study was a comparative investigation into the nature of difficulties in learning English by the secondary school students of Provincial and Federal government schools in N.W.F.P (Khyber Pukhtunkhwa). The objectives of the study were (1)To find out the level of difficulties of secondary school students of Provincial and Federal government schools of N.W.F.P (Khyber Pukhtunkhwa) in tenses, active and passives voices, direct and indirect narrations, conjunctions, prepositions, articles, construction of sentences and reading with comprehension and (2)To compare the level of difficulties in learning English as a second language at secondary level of Provincial and Federal government schools in N.W.F.P (Khyber Pukhtunkhwa). The sample of the study was comprised of 654 randomly selected students from twenty four Provincial government schools and twenty two Federal government schools located in twenty four districts of N.W.F.P. (Khyber Pukhtunkhwa). An English language achievement test for secondary classes was administered to the sample students of the study. The data obtained were tabulated and analyzed through SPSS 17.0 software to compute mean, standard deviation, t-value and p-value (significance) level. The main findings of the study were; the students of Provincial government schools faced more difficulties in learning of verb forms, narration, conjunctions, prepositions, articles, sentence arrangements and reading comprehension. The students of both types of schools systems faced same difficulties in learning voices. Key words: Nature of Difficulties, Tenses, Voices, Narrations, Conjunctions, Prepositions, Articles

Quantitative determination of alliin in dried garlic cloves and products by high-performance thin-layer chromatography

Purpose: To standardize the garlic samples and its products for alliin contents.Methods: A direct high-performance thin-layer chromatographic (HPTLC) method was developed to determine alliin in Chinese (CG) and Indian garlic (IG) and two other marketed products from USA and UK, respectively. Scanning and quantification were performed at 205 nm. Furthermore, chromatography was performed on pre-coated HPTLC plates with the solvent mixture, n – hexane:ethyl acetate (29:1 v/v), as the mobile phase. In addition, the parameters suggested by International Conference on Harmonization for analytical procedures were considered to validate the proposed method.Results: The system gave a compact spot of alliin at RF = 0.19 ± 0.01 The linear regression data for the calibration plots showed a good linearity (r2 = 0.996) in the concentration range of 200 - 1600 ng. Linear regression equation was represented by Y = 1.792x + 182.855, while LOD and LOQ values were 40.42 ngband-1 and 111.72 ng.band-1, respectively. The method showed excellent accuracy with recovery of 98.20 – 99.10 % and good precision with RSD of 1 - 2.65 %.Conclusion: The proposed method is selective, sensitive and accurate for the determination of alliin in garlic and its products. It is also evident from the results obtained that raw Indian garlic has higher alliin content than Chinese garlic.Keywords: Garlic, HPTLC, Alliin, Hypercholesteremia, Quantificatio

Digitalization, Sustainability and Development in Business. Business Intelligence - The Innovative Solutions for Business Sustainability, Equality, and Green Initiatives of Long-Term Organisational Performance

Business Intelligence (BI) encompasses a suite of strategies, processes, applications, and technologies that convert raw data into valuable insights for business analysis. By aiding in informed decision-making, BI empowers organizations to enhance their competitive edge and streamline internal operations. It not only uncovers new prospects but also refines customer service and bolsters profitability. Through historical, real-time, and predictive perspectives on business operations, BI facilitates well-informed choices. Leveraging BI tools, businesses dissect consumer behavior, detect trends, and devise potent marketing tactics. BI amplifies comprehension of customers, rivals, and markets, leading to astute decisions that foster profitability. This study amassed data via a survey of 162 IT managers in multinational corporations within Malaysia. Employing partial least squares (PLS) through SmartPLS software, the analysis reveals that BI, along with its insights, contributes to effective management practices. Notably, the information requisites may shift based on the balance between uncertainty and ambiguity in an organization’s practices. Nevertheless, the research gap remains concerning the relationship between BI, its significance, and business performance. Keywords: business intelligence, data analytics, data mining, big dat