Browsing by Author "Kumar, Atul"

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Bell�s inequality with biased experimental settings
(Springer, 2022-04-30T00:00:00) Singh, Parvinder; Faujdar, Jyoti; Sarkar, Maitreyee; Kumar, Atul
We analyse the efficiency of nonlocal correlations in comparison with classical correlations under biased experimental set-up, e.g. for a nonlocal game or a class of Bell-CHSH inequality where both Alice and Bob choose their measurements with a certain bias. We demonstrate that the quantum theory offers advantages over classical theory for the whole range of biasing parameters except for the limiting cases. Moreover, by using fine-grained uncertainty relations to distinguish between classical, quantum and superquantum correlations, we further confirm the underlined advantage of quantum correlations over classical correlations. Our results clearly show that all pure bi-partite entangled states violate the Bell-CHSH inequality under biased set-up. Although for the two-qubit mixed Werner state, the Horodecki state and a state proposed by Ma et al. (Phys Lett A 379:2802, 2015) the range of violation is same in both biased and unbiased scenarios, the extent of violation is different in both cases. We extend our analysis to detect nonlocal correlations using quantum Fisher information and demonstrate a necessary condition for capturing nonlocality in biased scenario. Furthermore, we also describe properties of nonlocal correlations under noisy conditions considering a biased experimental set-up. � 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
Entanglement and separability of graph Laplacian quantum states
(Springer, 2022-04-07T00:00:00) Joshi, Anoopa; Singh, Parvinder; Kumar, Atul
In this article, we study the entanglement properties of multi-qubit quantum states using a graph-theoretic approach. For this, we define entanglement and separability for m-qubit quantum states associated with a weighted graph on 2 m vertices. We further explore the properties of a block graph and a star graph to demonstrate criteria for entanglement and separability of these graphs. � 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
Evaluation of synergistic adsorption approach for terbinafine removal by cotton shell powder immobilized zerovalent copper: Adsorption kinetics and DFT simulation
(Elsevier B.V., 2023-08-30T00:00:00) Kaur, Parminder; Hussain, Khadim; Kumar, Atul; Singh, Janpreet; Nagendra Babu, J.; Kumar, Sandeep
Cotton shell powder (CS), nano zerovalent copper (nZVC) and cotton shell powder immobilized zerovalent copper (ZVC@CS) were evaluated for their adsorption efficiencies towards terbinafine hydrochloride (TBH), an antifungal drug. The nZVC and ZVC@CS synthesized via one pot redox precipitation method were characterized by FTIR, XRD, BET, FESEM and TGA analysis. The TGA and AAS analysis confirmed the loading of nearly 10% of nZVC on cotton shell powder in ZVC@CS. The effect of operational parameters (pH, adsorbent dose, initial drug concentration, time, etc.) determining the extent of terbinafine hydrochloride adsorption on ZVC@CS were investigated to ascertain the optimal experimental conditions to achieve maximum adsorption efficiencies. To investigate the adsorption behavior of TBH on ZVC@CS, the experimental data were fitted for five different adsorption models viz. Langmuir, Freundlich, Temkin, Redlich-Peterson and Hill isotherms. The TBH adsorption data was best fit with Hill isotherm model indicating cooperative sorption of TBH molecules on ZVC@CS surface. Among the five kinetic equations namely the pseudo-first-order (PFO), the pseudo-second-order (PSO), Elovich model, the intraparticle diffusion model, and Boyd kinetic model used to estimate the adsorption mechanism, the PFO kinetic model give best fit with a good correlation for the physisorption of TBH on ZVC@CS composite. The mechanism of the adsorption process was observed to be complex, consisting of both surface adsorption and pore diffusion. However, the Boyd plot confirms external mass transport as the rate limiting step for the adsorption of TBH on ZVC@CS. The synergistic adsorption of TBH on ZVC@CS was hypothesized, and the idea was supported by structure optimization results from DFT studies. The ZVC@CS exhibits equilibrium TBH adsorption efficiency (qmax) of 285.3 mg.g?1, significantly higher than adsorbents used in literature for the TBH removal. It is suggested that ZVC@CS may serve as sustainable adsorbents for the removal of cationic contaminants from acidic medium. � 2023 Elsevier B.V.
Nonlocality and efficiency of three-qubit partially entangled states
(Birkhauser, 2022-09-08T00:00:00) Faujdar, Jyoti; Kaur, Hargeet; Singh, Parvinder; Kumar, Atul; Adhikari, Satyabrata
We analyse nonlocal properties in three-qubit partially entangled Wn states to understand the efficiency of these states as entangled resources. Our results show that Wn states always violate the three-qubit Svetlichny inequality, and the degree of violation increases with the increase in degree of entanglement. We find that nonlocal correlations in W1 states are the highest in comparison to all other Wn states. We further demonstrate that within the limits of experimentally achievable measurements the W1 state proves to be a better quantum resource for specific protocols in comparison to standard W states, even though the degree of entanglement and nonlocality in the W1 state are less than the degree of entanglement and nonlocality in the standard W state. Moreover, we also consider superpositions of the Greenberger�Horne�Zeilinger (GHZ) state with W and W1 states to show that more entanglement is not a necessity for better efficiency in all protocols. In addition, we also demonstrate the preparation of three qubit quantum states represented as linear superpositions of the GHZ state with W and W1 states. � 2022, The Author(s) under exclusive license to Chapman University.
The role of entanglement for enhancing the efficiency of quantum kernels towards classification
(Elsevier B.V., 2023-06-19T00:00:00) Sharma, Diksha; Singh, Parvinder; Kumar, Atul
Quantum kernels are considered as potential resources to illustrate benefits of quantum computing in machine learning. Considering the impact of hyperparameters on the performance of a classical machine learning model, it is imperative to identify promising hyperparameters using quantum kernel methods in order to achieve quantum advantages. In this work, we analyse and classify sentiments of textual data using a new quantum kernel based on linear and full entangled circuits as hyperparameters for controlling the correlation among words. We also find that the use of linear and full entanglement further controls the expressivity of the Quantum Support Vector Machine (QSVM). In addition, we also compare the efficiency of the proposed circuit with other quantum circuits and classical machine learning algorithms. Our results show that the proposed fully entangled circuit outperforms all other fully or linearly entangled circuits in addition to classical algorithms for most of the features. In fact, as the feature increases the efficiency of our proposed fully entangled model also increases significantly. � 2023 Elsevier B.V.
Tetracycline removal via three-way synergy between pistachio shell powder, zerovalent copper or iron, and peroxymonosulfate activation
(Elsevier B.V., 2023-10-20T00:00:00) Kaur, Parminder; Kumar, Atul; Babu, J. Nagendra; Kumar, Sandeep
Pistachio shell powder (PS) immobilized zerovalent iron and zerovalent copper (ZVI@PS and ZVC@PS) were investigated for the tetracycline (TCH) removal via sulfate radical based advanced oxidation process (S-AOP's). Eco-efficient ZVI@PS and ZVC@PS nanocomposite prepared by one-pot redox precipitation method were characterized by using FTIR, XRD, SEM, BET, TGA/DTA, and XPS techniques. The EDX, TGA, and AAS analysis techniques confirmed the loading of 44 % Fe and 40 % Cu (w/w %) onto the pistachio shell biomass in ZVI@PS and ZVC@PS nanocomposites, respectively. This report comprehensively discusses the effect of various contributing factors for the TCH removal via advanced oxidation processes such as catalytic dosage, initial pH, PMS dosage and initial TCH concentrations, etc. Besides that, the role of reactive oxygen species (SO4?,.OH, O2?, and 1O2) in the TCH degradation process was investigated using radical scavenging experiments. A three-way synergistic approach was established between adsorption efficiencies of pistachio shell powder, heterogeneous ZVI or ZVC mediated Fenton-process and enhanced PMS activation process, for the observed enhanced TCH degradations. The observed rate constant (kobs.) values of ZVI@PS-PMS (0.34 min?1) and ZVC@PS-PMS (0.16 min?1) processes for TCH removal suggests that the ZVI@PS was more efficient in TCH removal compared to ZVC@PS. � 2023 The Author(s)