A5005627118- Atomic and Molecular Physics
- Advanced Chemical Physics Studies
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced Frequency and Time Standards
- Nuclear physics research studies
- Atomic and Subatomic Physics Research
- GaN-based semiconductor devices and materials
- Thermal properties of materials
- Quantum, superfluid, helium dynamics
- Mass Spectrometry Techniques and Applications
- Scientific Measurement and Uncertainty Evaluation
- Quantum optics and atomic interactions
- Quantum Chromodynamics and Particle Interactions
- Radioactive Decay and Measurement Techniques
- Quantum Mechanics and Applications
- Advanced NMR Techniques and Applications
- Acoustic Wave Resonator Technologies
- Radioactivity and Radon Measurements
- Rare-earth and actinide compounds
- Graphene research and applications
- Quantum and electron transport phenomena
- Advanced Physical and Chemical Molecular Interactions
- Electron and X-Ray Spectroscopy Techniques
- Quantum Computing Algorithms and Architecture
- Semiconductor Quantum Structures and Devices
Physical Research Laboratory
2016-2025
Vivekananda Global University
2024
C.V. Raman Global University
2024
National Institute of Technology Raipur
2011-2024
Bhabha Atomic Research Centre
2016-2024
Indian Institute of Technology Bombay
2024
Obayashi (Japan)
2023
Nagoya University
2023
RIKEN Nishina Center
2023
Optica
2020-2021
Nuclear charge radii are sensitive probes of different aspects the nucleon-nucleon interaction and bulk properties nuclear matter; thus, they provide a stringent test challenge for theory. The calcium region has been particular interest, as experimental evidence suggested new magic number at $N = 32$ [1-3], while unexpectedly large increases in [4,5] open questions about evolution size neutron-rich systems. By combining collinear resonance ionization spectroscopy method with $\beta$-decay...
Abstract The development of atomic many-body methods, capable incorporating electron correlation effects accurately, is required for isotope shift (IS) studies. In combination with precise measurements, such calculations help to extract nuclear charge radii differences, and probe signatures physics beyond the Standard Model particle physics. We review here a few recently-developed methods in relativistic perturbation theory (RMBPT) coupled-cluster (RCC) frameworks IS factors highly charged...
We report on a theoretical analysis of the suitability $7s\phantom{\rule{0.2em}{0ex}}^{2}S_{1∕2}\ensuremath{\leftrightarrow}6d\phantom{\rule{0.2em}{0ex}}^{2}D_{3∕2}$ transition in singly ionized radium to measure parity nonconservation, light an experiment planned at KVI University Groningen. Relativistic coupled-cluster theory has been employed perform ab initio calculation parity-nonconserving electric dipole amplitude this transition, including single, double, and leading triple...
Attempts are made to unify gravity with the other three fundamental forces of nature. As suggested by higher dimensional models, this unification may require space and time variation some dimensionless constants. In scenario, probing temporal electromagnetic fine structure constant <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m1"><mml:mrow><mml:mo...
We demonstrate that the $4{f}^{14}6s6p\phantom{\rule{0.16em}{0ex}}(^{3}P_{2})\ensuremath{-}4{f}^{13}5d6{s}^{2}\phantom{\rule{0.16em}{0ex}}(^{3}P_{2}^{*})$ transition in neutral ytterbium (Yb) can serve as an additional clock with highest fine-structure constant (${\ensuremath{\alpha}}_{e}$) varying sensitivity coefficient $[q=\ensuremath{-}46165(3000)]$. a scheme to attain simultaneous magic trapping conditions for this other two proposed transitions...
The electric dipole moment (EDM) of paramagnetic atoms is sensitive to the intrinsic EDM contribution from that its constituent electrons and a scalar-pseudoscalar (S-PS) electron-nucleus interaction. electron S-PS contributions EDMs these scale as $\ensuremath{\approx}{Z}^{3}$. Thus, heavy will exhibit large enhancement factors. However, sizes couplings are so small they interest high precision atomic experiments. In this work we have computed factors ground states Rb Cs due both using...
We study the cancellation of differential ac Stark shifts in 5s and 5p states rubidium atom using linearly circularly polarized lights by calculating their dynamic polarizabilities. Matrix elements were calculated a relativistic coupled-cluster method at single, double important valence triple excitations approximation including all possible non-linear correlation terms. Some matrix further optimized experimental results available for lifetimes static polarizabilities atomic states. "Magic...
We report the implementation of a general-order relativistic coupled-cluster method for performing high-precision calculations atomic and molecular properties. As first application, black-body radiation shift Al${}^{+}$ clock has been estimated precisely. The computed relative to frequency $3{s}^{2} {}^{1}{S}_{0}^{e}\ensuremath{\rightarrow}3s3p {}^{3}{P}_{0}^{o}$ transition given by...
We analyze atomic structures of plasma embedded aluminum (Al) atom and its ions in the weakly strongly coupling regimes. The screening effects these systems are accounted for using Debye ion sphere (IS) potentials plasmas, respectively. Within model, special attention is given to investigate spherical non-spherical plasma-screening considering electron-electron interaction potential. relativistic coupled-cluster (RCC) method has been employed describe electronic correlation above systems....
Electric dipole polarizability $({\ensuremath{\alpha}}_{d})$ and the electric moment (EDM) due to electron-nucleus tensor-pseudotensor (T-PT) nuclear Schiff (NSM) interactions are accurately determined for $^{199}\mathrm{Hg}$. Relativistic many-body methods at different levels of approximations employed gain insights into passage electron correlation effects in evaluation these properties. Significant changes results compared previous calculations observed. We estimate our final EDM be...
Our improved calculation of the nuclear spin-independent parity violating electric dipole transition amplitude ($E1_{PV}$) for $6s ~ ^2S_{1/2} - 7s ^2S_{1/2}$ in $^{133}$Cs combination with most accurate (0.3\%) measurement this quantity yields a new value weak charge $Q_W=-73.71(26)_{ex} (23)_{th}$ against Standard Model (SM) prediction $Q_W^{\text{SM}}=-73.23(1)$. The advances our $E1_{PV}$ have been achieved by using variant perturbed relativistic coupled-cluster theory which treats...
Through the examination of energy level crossings among fine-structure manifolds $(n=4\ensuremath{-}5){d}^{6}$ and $(n=4\ensuremath{-}5){d}^{8}$ configurations in a number highly charged ions (HCIs), we identify forbidden transitions that can be suitable for making single-ion-based optical clocks. These clock exhibit quality factors ranging between ${10}^{16}$ ${10}^{18}$, which are larger than most previously proposed HCI candidates. They also show high sensitivity to temporal variation...
We report the result of our ab initio calculation $6{s}^{2}{S}_{1/2}\ensuremath{\rightarrow}5{d}^{2}{D}_{3/2}$ parity nonconserving electric dipole transition amplitude in $^{137}\mathrm{Ba}^{+}$ based on relativistic coupled-cluster theory. Considering single, double, and partial triple excitations, we have achieved an accuracy less than 1%. If can be matched by proposed nonconservation experiment ${\mathrm{Ba}}^{+}$ for above transition, then combination two results would provide...
We investigate the role of electron correlation effects in electric-dipole polarizabilities ground states alkaline earth metals, helium, and ytterbium by employing relativistic coupled-cluster (RCC) theory. These are incorporated via residual Coulomb interaction to all orders RCC singles doubles approximations. The perturbed wave functions used calculations obtained directly solving first-order equations, thereby avoiding sum-over-states approach. Our results compared with other available...
A relativistic many-body theory for the electric dipole moment (EDM) of paramagnetic atoms arising from electron is presented and implemented. The coupled-cluster method with single double excitations (RCCSD) using Dirac-Coulomb Hamiltonian a weak parity time reversal violating interaction to first-order perturbation has been employed obtain EDM enhancement factor ground state Fr atom due intrinsic electron. trends different correlation effects leading contributions physical states are...
Appraising the projected $10^{-18}$ fractional uncertainty in optical frequency standards using singly ionized ions, we estimate black-body radiation (BBR) shifts due to magnetic dipole (M1) and electric quadrupole (E2) multipoles of fields, respectively. Multipolar scalar polarizabilities are determined for calcium (Ca$^+$) strontium (Sr$^+$) ions relativistic coupled-cluster method; though theory can be exercised any single ion clock proposal. The expected energy respective transitions...
We employ the closed-shell perturbed relativistic coupled-cluster (RCC) theory developed by us earlier [Phys. Rev. A {\bf 77}, 062516 (2008)] to evaluate ground state static electric dipole polarizabilities (\alpha s) of several atomic systems. In this work, we have incorporated a class higher order many-body effects in our calculations that had not been taken into account above paper. highlight their importance improving accuracy $\alpha$. also calculate \alpha s inert gas atoms and...
We demonstrate the importance of electron correlation effects in hyperfine structure constants many low-lying states $^{210}$Fr and $^{212}$Fr. This is achieved by calculating magnetic dipole electric quadrupole using Dirac-Fock approximation, second order many-body perturbation theory coupled-cluster method singles doubles approximation relativistic framework. By combining our recommended theoretical results with corresponding experimental values, improved nuclear moments above isotopes are...
Using accurate dynamic polarizabilities of the Li, Na, K, and Rb atoms, we scrutinize thermal Casimir-Polder interactions these atoms with a single-layered graphene. Considering modified Lifshitz theory for material interactions, reanalyze dispersion coefficient $({C}_{3})$ values above graphene as functions separation distance, gap parameter, temperature, among which some them were earlier studied by estimating using single oscillator model. All ${C}_{3}$ coefficients have been evaluated in...
Accurate knowledge of interaction potentials among the alkali-metal atoms and alkaline-earth ions is very useful in studies cold atom physics. Here we carry out theoretical long-range interactions Li, Na, K, Rb with ${\mathrm{Ca}}^{+}$, ${\mathrm{Ba}}^{+}$, ${\mathrm{Sr}}^{+}$, ${\mathrm{Ra}}^{+}$ systematically, which are largely motivated by their importance a number applications. These expressed as power series inverse internuclear separation $R$. Both dispersion induction components...
With increasing demand for accurate calculation of isotope shifts atomic systems fundamental and nuclear structure research, an analytic energy derivative approach is presented in the relativistic coupled-cluster theory framework to determine field shift mass factors. This allows determination expectation values operators, overcoming problems that are present existing physics methods, i.e. it satisfies Hellmann-Feynman theorem, does not involve any non-terminating series, free from choice...
Accurate calculations of electric dipole polarizabilities ($\alpha_d$), quadrupole moments ($\Theta$), and ($\alpha_q$) for the clock states singly charged calcium (Ca$^+$) ytterbium (Yb$^+$) ions are presented using general-order relativistic coupled-cluster (RCC) theory. Precise knowledge these quantities is immensely useful estimating uncertainties caused by major systematic effects such as linear quadratic Stark shifts black-body radiation in optical Ca$^+$ Yb$^+$ clocks. A finite-field...