Mathematical Physics, Nuclear and High Energy Physics, Statistical and Nonlinear Physics, Applied Mathematics
27
Scopus Publications
64
Scholar Citations
4
Scholar h-index
2
Scholar i10-index
Scopus Publications
Tuning the separability in noncommutative space Pinaki Patra AIP Publishing With the help of the generalized Peres–Horodecki separability criterion (Simon’s condition) for a bipartite Gaussian state, we have studied the separability of the noncommutative (NC) space coordinate degrees of freedom. Non-symplectic nature of the transformation between the usual commutative space and NC space restricts the straightforward use of Simon’s condition in NCS. We have transformed the NCS system to an equivalent Hamiltonian in commutative space through the Bopp shift, which enables the utilization of the separability criterion. To make our study fairly general and to analyze the effect of parameters on the separability of bipartite state in NC-space, we have considered a bilinear Hamiltonian with time-dependent (TD) parameters, along with a TD external interaction, which is linear in field modes. The system is transformed (Sp(4,R)) into canonical form keeping the intrinsic symplectic structure intact. The solution of the TD-Schrödinger equation is obtained with the help of the Lewis–Riesenfeld invariant method (LRIM). Expectation values of the observables (thus the covariance matrix) are constructed from the states obtained from LRIM. It turns out that the existence of the NC parameters in the oscillator determines the separability of the states. In particular, for isotropic oscillators, the separability condition for the bipartite Gaussian states depends on specific values of NC parameters. Moreover, particular anisotropic parameter values for the oscillator may cease the separability. In other words, both the deformation parameters (θ, η) and parameter values of the oscillator (mass, frequency) are important characteristics for the separability of bipartite Gaussian states. Thus tuning the parameter values, one can destroy or recreate the separability of states. With the help of a toy model, we have demonstrated how the tuning of a TD-NC space parameter affects the separability.
On the entanglement of co-ordinate and momentum degrees of freedom in noncommutative space Shilpa Nandi, Muklesur Rahaman, and Pinaki Patra World Scientific Pub Co Pte Ltd In this paper, we investigate the quantum entanglement induced by phase-space noncommutativity. Both the position–position and momentum–momentum noncommutativity are incorporated to study the entanglement properties of coordinate and momentum degrees of freedom under the shade of oscillators in noncommutative space. Exact solutions for the systems are obtained after the model is re-expressed in terms of canonical variables, by performing a particular Bopp’s shift to the noncommuting degrees of freedom. It is shown that the bipartite Gaussian state for an isotropic oscillator is always separable. To extend our study for the time-dependent system, we allow arbitrary time dependency on parameters. The time-dependent isotropic oscillator is solved with the Lewis–Riesenfeld invariant method. It turns out that even for arbitrary time-dependent scenarios, the separability property does not alter. We extend our study to the anisotropic oscillator, which provides an entangled state even for time-independent parameters. The Wigner quasi-probability distribution is constructed for a bipartite Gaussian state. The noise matrix (covariance matrix) is explicitly studied with the help of Wigner distribution. Simon’s separability criterion (generalized Peres–Horodecki criterion) has been employed to find the unique function of the (mass and frequency) parameters, for which the bipartite states are separable. In particular, we show that the mere inclusion of non-commutativity of phase-space is not sufficient to generate the entanglement, rather anisotropy is important at the same footing. We explore the experimental viability of our result through the computation of extractable work for the current situation.
On the two-dimensional time-dependent anisotropic harmonic oscillator in a magnetic field Pinaki Patra AIP Publishing A charged harmonic oscillator in a magnetic field, Landau problems, and an oscillator in a noncommutative space share the same mathematical structure in their Hamiltonians. We have considered a two-dimensional anisotropic harmonic oscillator with arbitrarily time-dependent parameters (effective mass and frequencies), placed in an arbitrarily time-dependent magnetic field. A class of quadratic invariant operators (in the sense of Lewis and Riesenfeld) have been constructed. The invariant operators (Î) have been reduced to a simplified representative form by a linear canonical transformation [the group Sp(4,R)]. An orthonormal basis of the Hilbert space consisting of the eigenvectors of Î is obtained. In order to obtain the solutions of the time-dependent Schrödinger equation corresponding to the system, both the geometric and dynamical phase-factors are constructed. A generalized Peres–Horodecki separability criterion (Simon’s criterion) for the ground state corresponding to our system has been demonstrated.
Improvement of accelerating gradients in niobium quarter wave resonators A Rai, P N Potukuchi, P Patra, G K Chaudhari, S S K Sonti, J Karmakar, B Karmakar, A Sharma, D S Mathuria, A Pandey,et al. IOP Publishing Systematic studies have been performed on the effect of the surface processing techniques for improving accelerating gradients in superconducting niobium quarter wave resonators (QWR). These include high pressure rinsing (HPR), high temperature heat treatment of cavities and helium pulse processing. Tests done after HPR have not only shown a reduction in field emission in the cavities at high accelerating gradients but also an improvement in the low field quality factor (Q). The effect of the high temperature (650 °C) heat treatment of jacketed QWRs (QWR with the outer helium vessel) on the cavity gradients has also been investigated. This was performed for two different QWR designs and a substantial improvement in performance has been observed in both the cases. The increase in gradients is beyond that due to hydrogen degassing alone. Helium pulse processing during 4 K tests has been tried out on several cavities and its effect on the quality factor at both high and low gradients has been observed. This technique has been found to be useful for those resonators which have a high Q at lower fields but are limited due to the field emission at higher gradients. They have exhibited a marked improvement in the high field Q-slope over and above that obtained with conventional pulse processing under high vacuum. A comprehensive overview of all these developments carried out over the past few years has been reported.
The first phase of the pre-bunched Free Electron Laser (FEL) based on the RF electron gun, has been initiated at Inter University Accelerator Centre (IUAC), New Delhi. The photoinjector-based electron gun made from OFHC copper was fabricated and tested with low power RF. The beam optics calculation by using ASTRA and GPT codes are performed and radiation produced from the pre-bunched electron bunches are being calculated. The high-power RF system was ordered and will be commissioned at IUAC by the beginning of 2018. The design of the laser system is being finalised and assembly/testing of the complete laser system will be started soon in collaboration with KEK, Japan. The initial design of the photocathode deposition system has been completed and its procurement/de-velopment process is also started. The first version of the undulator magnet design is completed and its further im-provements are underway. The initial design of the DLS beam line have been worked out and various beam diag-nostics components are being finalised. Production
Status of design and development of Delhi Light Source at Iuac, Delhi
Modified Hamiltonian formalism for Regge-Teitelboim cosmology Pinaki Patra, Md. Raju, Gargi Manna, and Jyoti Prasad Saha Hindawi Limited The Ostrogradski approach for the Hamiltonian formalism of higher derivative theory is not satisfactory because the Lagrangian cannot be viewed as a function on the tangent bundle to coordinate manifold. In this paper, we have used an alternative approach which leads directly to the Lagrangian which, being a function on the tangent manifold, gives correct equation of motion; no new coordinate variables need to be added. This approach can be used directly to the singular (in Ostrogradski sense) Lagrangian. We have used this method for the Regge-Teitelboim (RT) minisuperspace cosmological model. We have obtained the Hamiltonian of the dynamical equation of the scale factor of RT model.
Design of a compact light source Accelerator facility at IUAC, Delhi
Engineering wave localization in a fractal waveguide network Biplab Pal, Pinaki Patra, Jyoti Prasad Saha, and Arunava Chakrabarti American Physical Society (APS) We present an exact analytical method of engineering the localization of electromagnetic waves in a fractal waveguide network. It is shown that, a countable infinity of localized electromagnetic modes with a multitude of localization lengths can exist in a Vicsek fractal geometry built with diamond shaped monomode waveguides as the 'unit cells'. The family of localized modes form clusters of increasing size. The length scale at which the onset of localization for each mode takes place can be engineered at will, following a well defined prescription developed within the framework of a real space renormalization group. The scheme leads to an exact evaluation of the wave vector for every such localized state, a task that is non-trivial, if not impossible for any random or deterministically disordered waveguide network.
Superconducting linac at Inter-University Accelerator Centre: Operational challenges and solutions S. Ghosh, R. Mehta, G. K. Chowdhury, A. Rai, P. Patra, B. K. Sahu, A. Pandey, D. S. Mathuria, J. Chacko, A. Chowdhury,et al. American Physical Society (APS) A superconducting linear accelerator based on niobium quarter wave resonators has recently become operational to boost the energy of the heavy ion beams available from the existing 15 UD (unit doubled) Pelletron accelerator. The niobium resonators typically performed at an accelerating field of $3\\char21{}6\\text{ }\\text{ }\\mathrm{MV}/\\mathrm{m}$ at 6 watts of input power in the test cryostat. When they were tested in the linac cryostat, the accelerating fields were drastically reduced and a number of other problems were also encountered. At present, all the problems have been diagnosed and solved. Many design modifications, e.g., in power coupler, mechanical tuner, helium cooling system, etc. were incorporated to solve the problems. A novel method of vibration damping was also implemented to reduce the effect of microphonics on the resonators. Finally, the accelerated beam through linac was delivered to conduct experiments.
RECENT SCHOLAR PUBLICATIONS
Information geometry of entangled states induced by noncommutative deformation of phase space S Nandi, P Patra arXiv preprint arXiv:2502.05688 2025
On the entanglement of co-ordinate and momentum degrees of freedom in noncommutative space S Nandi, M Rahaman, P Patra Modern Physics Letters A 39 (19n20), 2450091 2024
Tuning the separability in noncommutative space P Patra Journal of Mathematical Physics 65 (5) 2024
On the -Symmetric Parametric Amplifier P Patra Brazilian Journal of Physics 54 (1), 24 2024
On the two-dimensional time-dependent anisotropic harmonic oscillator in a magnetic field P Patra Journal of Mathematical Physics 64 (4) 2023
Entanglement in phase-space distribution for an anisotropic harmonic oscillator in noncommutative space P Patra Quantum Information Processing 22 (1), 20 2022
Dynamics of the free time-dependent effective mass P Patra, A Chowdhury, M Jana The European Physical Journal Plus 137 (9), 1-9 2022
-symmetric Quantum systems for position-dependent effective mass violate the Heisenberg uncertainty principle P Patra arXiv preprint arXiv:2208.10336 2022
Squeezed coherent states for gravitational well in noncommutative space P Patra, JP Saha, K Biswas Indian Journal of Physics, 1-7 2022
Squeezed coherent state for free-falling Maxwell–Chern–Simons model in long-wavelength limit K Biswas, JP Saha, P Patra Indian Journal of Physics 95 (4), 647-655 2021
Entropy uncertainty principle for Dirac system with mass jump P Patra, K Biswas arXiv preprint arXiv:2007.12270 2020
Generalized Lewis-Riesenfeld invariance for dynamical effective mass in jammed granullar media under a potential well in non-commutative space K Biswas, JP Saha, P Patra arXiv preprint arXiv:2006.11252 2020
On the position-dependent effective mass Hamiltonian K Biswas, JP Saha, P Patra The European Physical Journal Plus 135 (6), 1-11 2020
Constraints on the choice of position dependent effective mass and external potential for the existence of Lewis-Riesenfeld invariance and quantum canonical transformation K Biswas, JP Saha, P Patra arXiv preprint arXiv:2003.13424 2020
Self-adjoint extension for Maxwell-Chern-Simons model in long wavelength limit P Patra, JP Saha, K Biswas arXiv preprint arXiv:1703.06797 2017
Current conservation in charge conjugation parity time reversal symmetry violating gauge-invariant nonlocal Thirring model P Patra, JP Saha Indian Journal of Physics 89, 87-90 2015
Quantum restoration of broken symmetry in one-dimensional loop space P Patra, T Mandal, JP Saha Pramana 82, 965-971 2014
Uncertainty principle guarantees genuine source of intrinsic randomness T Chakraborty, M Banik, P Patra Quantum information processing 13, 839-848 2014
Modified Hamiltonian Formalism for Regge‐Teitelboim Cosmology P Patra, M Raju, G Manna, JP Saha Physics Research International 2014 (1), 606727 2014
Lorentz Invariant CPT Violation for a Class of Nonlocal Thirring Model P Patra, JP Saha arXiv preprint arXiv:1305.5817 2013
MOST CITED SCHOLAR PUBLICATIONS
Engineering wave localization in a fractal waveguide network B Pal, P Patra, JP Saha, A Chakrabarti Physical Review A—Atomic, Molecular, and Optical Physics 87 (2), 023814 2013 Citations: 19
On the position-dependent effective mass Hamiltonian K Biswas, JP Saha, P Patra The European Physical Journal Plus 135 (6), 1-11 2020 Citations: 11
SUSY formalism for the symmetric double well potential P PATRA, A DUTTA, JP Saha Pramana, 1-10 Citations: 9
On the two-dimensional time-dependent anisotropic harmonic oscillator in a magnetic field P Patra Journal of Mathematical Physics 64 (4) 2023 Citations: 8
Squeezed coherent states for gravitational well in noncommutative space P Patra, JP Saha, K Biswas Indian Journal of Physics, 1-7 2022 Citations: 4
Entanglement in phase-space distribution for an anisotropic harmonic oscillator in noncommutative space P Patra Quantum Information Processing 22 (1), 20 2022 Citations: 3
Dynamics of the free time-dependent effective mass P Patra, A Chowdhury, M Jana The European Physical Journal Plus 137 (9), 1-9 2022 Citations: 3
Squeezed coherent state for free-falling Maxwell–Chern–Simons model in long-wavelength limit K Biswas, JP Saha, P Patra Indian Journal of Physics 95 (4), 647-655 2021 Citations: 3
Tuning the separability in noncommutative space P Patra Journal of Mathematical Physics 65 (5) 2024 Citations: 1
On the -Symmetric Parametric Amplifier P Patra Brazilian Journal of Physics 54 (1), 24 2024 Citations: 1
Generalized Lewis-Riesenfeld invariance for dynamical effective mass in jammed granullar media under a potential well in non-commutative space K Biswas, JP Saha, P Patra arXiv preprint arXiv:2006.11252 2020 Citations: 1
Uncertainty principle guarantees genuine source of intrinsic randomness T Chakraborty, M Banik, P Patra Quantum information processing 13, 839-848 2014 Citations: 1