Kinetic energy release distributions of multiply charged NOq+ (q = 2-7) molecular ions produced in collisions with 1.6 MeV Ar8+ ion beam Avijit Duley, Narendra Nath Dutta, Jatin Yadav, Rohit Tyagi, Sandeep B. Bari, et al. Journal of Chemical Physics, 2025 We report the fragmentation dynamics of multiply charged molecular ions of NO under the impact of highly charged Ar8+ ions in the intermediate velocity (vp ≈ 1 a.u.) range. Coincidence measurements of ionic fragments from NOq+ (2 ≤q≤ 7) were performed utilizing the three-dimensional momentum imaging technique of a recoil-ion momentum spectrometer equipped with a time- and position-sensitive detector and a multi-hit data acquisition system. With a 1.6 MeV Ar8+ beam, we observed a total of 13 fragmentation channels. Coulomb breakup of the unstable parent molecular ion shows a clear preference for the symmetric charge breakup over the asymmetric one. We have measured the Kinetic Energy Release Distributions (KERDs) for various fragmentation channels. We have also generated the potential energy curves for NOq+ molecular ions using the internally contracted multi-reference configuration interaction approach with complete active space self-consistent field wave functions. The obtained KERDs are compared and discussed in the background of the ab initio potential energy curves as well as the simple Coulomb explosion model.
Two-Photon Polarizability of Ba+ Ion: Control of Spin-Mixing Processes in an Ultracold 137Ba+ − 87Rb Mixture Arghya Das, Anal Bhowmik, Narendra Nath Dutta, Sonjoy Majumder Atoms, 2022 In this work, we present a scheme of a two-photon interaction to calculate magic wavelengths for the 62S12 − 52D32,52 clock transitions of Ba+ ion employing the relativistic coupled-cluster method. These magic wavelengths can be essential inputs to achieve better accuracy in the future ionic clock experiments. In this paper, we further show an application of a two-photon interaction to the spin-mixing processes, |0,0⟩↔|+1,−1⟩ and |0,0⟩↔|−1,+1⟩, of an ultra-cold spin-1 mixture of 137Ba+ ions and 87Rb atoms. We determine the protocols for selecting these spin-mixing oscillations by changing the strength and frequencies of the externally applied magnetic field and laser beams, respectively.
Vector polarizability of an atomic state induced by a linearly polarized vortex beam: External control of magic, tune-out wavelengths, and heteronuclear spin oscillations Anal Bhowmik, Narendra Nath Dutta, Sonjoy Majumder Physical Review A, 2020 Experiments with vortex beams have shown a surge of interest in controlling cold atoms. Most of the controlling protocols are dominated by circularly polarized light due to its ability to induce vector polarization at atoms, which is impossible for paraxial linearly polarized light. Here we develop a theory for frequency dependent polarizability of an atomic state interacting with a focused linearly polarized vortex beam. The naturally induced spin-orbit coupling in this type of linearly polarized beam produces vector component of the valence polarizability to an atomic state, obeying the total angular momentum conservation of the beam. The theory is employed on $^{87}$Sr$^{+}$ ion to accurately calculate the magic wavelengths for the clock transitions and tune-out wavelengths for the clock states using relativistic coupled-cluster method. The induced vector component in the dynamic polarizability due to the linearly polarized focused vortex beam promotes fictitious magnetic field to the atomic state. We demonstrate that this fictitious magnetic field, depending on the focusing angle and OAM of the beam, improves the flexibility of the coherent heteronuclear spin oscillations in a spin-1 mixture of $^{87}$Rb and $^{23}$Na atoms.
Many-body calculations and hyperfine-interaction effect on dynamic polarizabilities at the low-lying energy levels of Y2+ Arghya Das, Anal Bhowmik, Narendra Nath Dutta, Sonjoy Majumder Physical Review A, 2020 The present paper determines the precise values of magic wavelengths corresponding to the clock transitions ${5}^{2}S\\text{--}{4}^{2}D$ of the ${\\mathrm{Y}}^{2+}$ ion at the levels of both fine and hyperfine structures due to the external light beams having linear as well as circular polarization. To calculate the dynamic polarizabilities of the associated states of the transitions, we employ the sum-over-states technique, where the dominating and correlation sensitive part of the sum is evaluated using a highly correlated relativistic coupled-cluster theory. The estimated magic wavelengths of the light beams have substantial importance to cool and trap the ion using a blue-detuned trapping scheme. We also present the tune-out wavelengths, which are useful in state-insensitive trapping and cooling. The vector component of a total polarizability, which is induced by a circularly polarized light only, can provide additional magic wavelengths. Considerable effects of hyperfine interaction on the values of polarizabilities and number of magic wavelengths divulge the importance of precise estimations of hyperfine-structure splitting.
Improving "silver-Standard" Benchmark Interaction Energies with Bond Functions Narendra Nath Dutta, Konrad Patkowski Journal of Chemical Theory and Computation, 2018 We investigate the effect of adding midbond basis functions on the performance of various conventional and explicitly correlated (F12) estimates of complete basis set limit coupled-cluster (CCSD(T)/CBS) noncovalent interaction energies. In particular, we search for an improved "silver standard" of interaction energy calculations for systems where the CCSD(T) computation is feasible in a double-ζ basis but not in a triple-ζ one. We follow a recent study ( Sirianni J. Chem. Theory Comput. 2017 , 13 , 86 ) of different CCSD(T)-F12 variants in midbondless bases over the A24 and S22 benchmark interaction energy databases, and extend Dunning's correlation-consistent basis sets with three different midbond sets. The addition of bond functions is highly beneficial for conventional CCSD(T) and most CCSD(T)-F12 variants, improving both the CCSD part and the unscaled triples contribution. However, the commonly used scaling of triples by the ratio of the MP2-F12 and MP2 correlation energies usually overshoots: as a result, the scaled triples term gets worse upon the addition of bond functions. In contrast, a milder triples scaling by the ratio of the CCSD-F12b and CCSD correlation energies ( Brauer , Phys. Chem. Chem. Phys. 2016 , 18 , 20905 ) leads to the most accurate estimates of this term as long as bond functions are included. The combination of the triples term scaled in this way with the CCSD-F12b interaction energy leads to the CCSD(Tbb)-F12b approach that provides consistent high accuracy when a (3 s3 p2 d2 f) set of midbond functions is added to the aug-cc-pVDZ atom-centered basis set. The combination of midbond functions and the composite MP2/CBS+δ(CCSD(T)) treatment is able to make up for the deficiencies in the atom-centered part of the basis set, in particular, for a partial (or even complete) lack of diffuse functions. Considering both the A24 and S22 accuracy and the computational efficiency, we propose several new "silver standard" approaches improving upon the currently established midbondless levels of theory, ranging from the most consistent CCSD(Tbb)-F12b/aug-cc-pVDZ+(3 s3 p2 d2 f) variant (with mean unsigned errors of 0.010 and 0.042 kcal/mol for the A24 and S22 databases, respectively) to the significantly cheaper MP2/CBS+δ(CCSD(T))/cc-pVDZ+(3 s3 p2 d2 f) approach (mean unsigned errors of 0.039 and 0.096 kcal/mol for A24 and S22, respectively).
Tunable magic wavelengths for trapping with focused Laguerre-Gaussian beams Anal Bhowmik, Narendra Nath Dutta, Sonjoy Majumder Physical Review A, 2018 We present in this paper a theory of dynamic polarizability for an atomic state due to an external field of non-paraxial Laguerre-Gaussian (LG) beam using the sum-over-states technique. A highly correlated relativistic coupled-cluster theory is used to evaluate the most important and correlation sensitive parts of the sum. The theory is applied on Sr$^+$ to determine the magic wavelengths for $5s_{{1}/{2}}\\rightarrow 4d_{{3}/{2}, {5}/{2}}$ transitions. Results show the variation of magic wavelengths with the choice of orbital and spin angular momenta of the incident LG beam. Also, the tunability of the magic wavelengths is studied using the focusing angle of the LG beam and observed its efficiency in the near-infrared region. Evaluations of the wide spectrum of magic wavelengths from infrared to ultra-violet have substantial importance to the experimentalists for carrying out high precision measurements in fundamental physics. These magic wavelengths can be used to confine the atom or ion at the dark central node or at the high-intensity ring of the LG beam.
Electron-correlation study of y III-Tc VII ionsusing a relativistic coupled-cluster theory Arghya Das, Anal Bhowmik, Narendra Nath Dutta, Sonjoy Majumder Journal of Physics B Atomic Molecular and Optical Physics, 2018 Spectroscopic properties, useful for plasma diagnostics and astrophysics, of a few rubidium-like ions are studied here. We choose one of the simplest, but correlationally challenging series where d- and f-orbitals are present in the core and/or valence shells with 4 d 2 D 3 / 2 as the ground state. We study different correlation characteristics of this series and make precise calculations of electronic structure and rates of electromagnetic transitions. Our calculated lifetimes and transition rates are compared with other available experimental and theoretical values. Radiative rates of vacuum ultraviolet electromagnetic transitions of the long lived Tc6+ ion, useful in several areas of physics and chemistry, are estimated. To the best of our knowledge, there is no literature for most of these transitions.
Kinetic energy release distributions of multiply charged NOq+ (q= 2–7) molecular ions produced in collisions with 1.6 MeV Ar8+ ion beam A Duley, NN Dutta, J Yadav, R Tyagi, SB Bari, CP Safvan, AH Kelkar The Journal of Chemical Physics 163 (12) , 2025 2025
Two-Photon Polarizability of Ba + Ion: Control of Spin-Mixing Processes in an Ultracold 137 Ba + − 87 Rb Mixture A Das, A Bhowmik, NN Dutta, S Majumder Atoms 10 (4), 109 , 2022 2022 Citations: 1
Fragmentation dynamics of diatomic molecules under proton impact: Kinetic energy release spectra of CO and NO ( q = 2, 3) molecular ions A Duley, NN Dutta, C Bagdia, LC Tribedi, CP Safvan, AH Kelkar The European Physical Journal D 76 (9), 162 , 2022 2022 Citations: 5
Role of vector polarizability induced by a linearly polarized focused Laguerre–Gaussian light: applications in optical trapping and ultracold spinor mixture A Bhowmik, NN Dutta, S Das The European Physical Journal D 76 (8), 139 , 2022 2022 Citations: 2
Two-Photon Polarizability of Ba+ Ion: Control of Spin-Mixing Processes in an Ultracold 137Ba+-87Rb Mixture. Atoms 2022, 10, 109 A Das, A Bhowmik, NN Dutta, S Majumder s Note: MDPI stays neutral with regard to jurisdictional claims in published … , 2022 2022
Two-photon polarizability of Ba ion: Control of spin-mixing process in an ultracold Ba -- Rb mixture A Das, A Bhowmik, NN Dutta, S Majumder arXiv preprint arXiv:2106.09607 , 2021 2021
Vector polarizability of an atomic state induced by a linearly polarized vortex beam: External control of magic, tune-out wavelengths, and heteronuclear spin oscillations A Bhowmik, NN Dutta, S Majumder Physical Review A 102 (6), 063116 , 2020 2020 Citations: 9
Trend of Gaunt interaction contributions to the electric dipole polarizabilities of noble gas, alkaline-earth, and a few group-12 atoms NN Dutta Chemical Physics Letters 758, 137911 , 2020 2020 Citations: 7
Many-body calculations and hyperfine-interaction effect on dynamic polarizabilities at the low-lying energy levels of A Das, A Bhowmik, NN Dutta, S Majumder Physical Review A 102 (1), 012801 , 2020 2020 Citations: 7
Precise many-body calculations and hyperfine interaction effect on dynamic polarizabilities at the low-lying energy levels of Y A Das, A Bhowmik, NN Dutta, S Majumder arXiv preprint arXiv:1809.06897 , 2018 2018
Improving "silver-standard" benchmark interaction energies with bond functions NN Dutta, K Patkowski Journal of Chemical Theory and Computation 14 (6), 3053 , 2018 2018 Citations: 25
Tunable magic wavelengths for trapping with focused Laguerre-Gaussian beams A Bhowmik, NN Dutta, S Majumder Physical Review A 97 (2), 022511 , 2018 2018 Citations: 19
Precise Calculations of Astrophysically Important Allowed and Forbidden Transitions of Xe viii A Bhowmik, NN Dutta, S Roy The Astrophysical Journal 836 (1), 125 , 2017 2017 Citations: 14
Electron-correlation study of Y III-Tc VII ions using a relativistic coupled-cluster theory A Das, A Bhowmik, NN Dutta, S Majumder Journal of Physics B: At., Mol. Opt. Phys. 51 (2), 025001 , 2017 2017 Citations: 21
Study of coupled-cluster correlations on electromagnetic transitions and hyperfine structure constants of W VI A Bhowmik, S Roy, NN Dutta, S Majumder Journal of Physics B: At., Mol. Opt. Phys. 50 (12), 125005 , 2017 2017 Citations: 17
Ab initio calculations of spectroscopic properties of Cr5+ using coupled-cluster theory NN Dutta, S Majumder Indian Journal of Physics 90 (4), 373 , 2016 2016 Citations: 17
Dynamic polarizabilities and hyperfine-structure constants for NN Dutta, S Roy, PC Deshmukh Physical Review A 92 (5), 052510 , 2015 2015 Citations: 12
Hyperfine and Parity Non-conserving Interactions in Alkali-Metal-Like Atoms and Ions NN Dutta 2015 Citations: 2
parity-nonconserving transition amplitudes of the hyperfine components for transitions of and NN Dutta, S Majumder Physical Review A 90 (1), 012522 , 2014 2014 Citations: 18
PNC transition amplitudes of the hyperfine components for transitions of Ba and Sr NN Dutta, S Majumder arXiv preprint arXiv:1404.2020 , 2014 2014
MOST CITED SCHOLAR PUBLICATIONS
Effect of screening on spectroscopic properties of Li-like ions in a plasma environment PK Mondal, NN Dutta, G Dixit, S Majumder Physical Review A—Atomic, Molecular, and Optical Physics 87 (6), 062502 , 2013 2013 Citations: 31
Ab initio studies of electron correlation and Gaunt interaction effects in the boron isoelectronic sequence using coupled-cluster theory NN Dutta, S Majumder Physical Review A 85 (3), 032512 , 2012 2012 Citations: 27
Improving "silver-standard" benchmark interaction energies with bond functions NN Dutta, K Patkowski Journal of Chemical Theory and Computation 14 (6), 3053 , 2018 2018 Citations: 25
Electron-correlation study of Y III-Tc VII ions using a relativistic coupled-cluster theory A Das, A Bhowmik, NN Dutta, S Majumder Journal of Physics B: At., Mol. Opt. Phys. 51 (2), 025001 , 2017 2017 Citations: 21
Ab initio calculations of transition amplitudes and hyperfine A and B constants of Ga III, NN Dutta, S Roy, G Dixit, S Majumder Physical Review A 87 (1), 012501 , 2013 2013 Citations: 20
Tunable magic wavelengths for trapping with focused Laguerre-Gaussian beams A Bhowmik, NN Dutta, S Majumder Physical Review A 97 (2), 022511 , 2018 2018 Citations: 19
parity-nonconserving transition amplitudes of the hyperfine components for transitions of and NN Dutta, S Majumder Physical Review A 90 (1), 012522 , 2014 2014 Citations: 18
Study of coupled-cluster correlations on electromagnetic transitions and hyperfine structure constants of W VI A Bhowmik, S Roy, NN Dutta, S Majumder Journal of Physics B: At., Mol. Opt. Phys. 50 (12), 125005 , 2017 2017 Citations: 17
Ab initio calculations of spectroscopic properties of Cr5+ using coupled-cluster theory NN Dutta, S Majumder Indian Journal of Physics 90 (4), 373 , 2016 2016 Citations: 17
Accurate estimations of stellar and interstellar transition lines of triply ionized germanium NN Dutta, S Majumder Astrophysical Journal 737 (1), 25 , 2011 2011 Citations: 15
Precise Calculations of Astrophysically Important Allowed and Forbidden Transitions of Xe viii A Bhowmik, NN Dutta, S Roy The Astrophysical Journal 836 (1), 125 , 2017 2017 Citations: 14
Dynamic polarizabilities and hyperfine-structure constants for NN Dutta, S Roy, PC Deshmukh Physical Review A 92 (5), 052510 , 2015 2015 Citations: 12
Vector polarizability of an atomic state induced by a linearly polarized vortex beam: External control of magic, tune-out wavelengths, and heteronuclear spin oscillations A Bhowmik, NN Dutta, S Majumder Physical Review A 102 (6), 063116 , 2020 2020 Citations: 9
Electron-correlation trends in the hyperfine A and B constants of the Na isoelectronic sequence NN Dutta, S Majumder Physical Review A 88 (6), 062507 , 2013 2013 Citations: 9
Relativistic coupled-cluster calculations on hyperfine structures and electromagnetic transition amplitudes of In III S Roy, NN Dutta, S Majumder Physical Review A 89 (4), 042511 , 2014 2014 Citations: 8
Trend of Gaunt interaction contributions to the electric dipole polarizabilities of noble gas, alkaline-earth, and a few group-12 atoms NN Dutta Chemical Physics Letters 758, 137911 , 2020 2020 Citations: 7
Many-body calculations and hyperfine-interaction effect on dynamic polarizabilities at the low-lying energy levels of A Das, A Bhowmik, NN Dutta, S Majumder Physical Review A 102 (1), 012801 , 2020 2020 Citations: 7
Fragmentation dynamics of diatomic molecules under proton impact: Kinetic energy release spectra of CO and NO ( q = 2, 3) molecular ions A Duley, NN Dutta, C Bagdia, LC Tribedi, CP Safvan, AH Kelkar The European Physical Journal D 76 (9), 162 , 2022 2022 Citations: 5
Role of vector polarizability induced by a linearly polarized focused Laguerre–Gaussian light: applications in optical trapping and ultracold spinor mixture A Bhowmik, NN Dutta, S Das The European Physical Journal D 76 (8), 139 , 2022 2022 Citations: 2
Hyperfine and Parity Non-conserving Interactions in Alkali-Metal-Like Atoms and Ions NN Dutta 2015 Citations: 2