An International Research Journal

AJP Vol 25 No 9,2016

AJP

SSN : 0971 - 3093

Vol 25, No 9, September, 2016

25th Anniversary Year of AJP-2016

Special issue

on

Advances in High Precision Spectroscopy and Tests of Fundamental Physics, Part-1

Edited by

Bijaya Kumar Sahoo

Asian Journal of Physics

(A Publication Not for Profit)

Vol. 25, No 9 (2016)

 CONTENTS


Guest Editorial                                                                               

About the Guest Editor

 

Prospect of molecular clocks

Masatoshi Kajita                                                                                                                                                                                                        1051

 

Oscillation frequencies for simultaneous trapping of heteronuclear alkali atoms                                                 

Kiranpreet Kaur, B K Sahoo and Bindiya Arora                                                                                                                                                        1061

 

Singly charged ions for optical clocks

N Batra, A Roy, S Majhi, S Panja and S De                                                                                                                                                             1069


Permanent EDM measurement in Cs using nonlinear magneto-optic rotation                                                                                                

Harish Ravi, Mangesh Bhattarai, Abhilash Y D, Ummal Momeen* and Vasant Natarajan                                                                                             1093

 

Precise many-electron calculations of isotope shift for alkali like atoms or ions                                                        

Sourav Roy, Anal Bhowmik and Sonjoy Majumder                                                                                                                                                    1103


Energy level crossing of highly charged ions for optical clocks

Yan-mei Yu and Bing-bing Suo                                                                                                                                                                                1119

 

The magnetic moment of the bound electron

G Werth and S Sturm                                                                                                                                                                                              1143


Computational methods for high-precision spectroscopy of three-electron atomic systems

Liming Wang, Chun Li, and Zong-Chao Yan                                                                                                                                                             1161


Precision measurements based on 40Ca+ ion optical frequency standards

Hua Guan, Yao Huang, Cheng-bin Li, Li-yan Tang, and Ke-lin Gao                                                                                                                           1207


Precision physics with molecules

Amar C Vutha                                                                                                                                                                                                       1233


Asian Journal of Physics                                                                                                     Vol. 25 No 9, 2016 1051-1059

 

Prospect of molecular clocks


Masatoshi Kajita

National Institute of Information and Communications Technology

Koganei, Tokyo 184-8795, JAPAN

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While uncertainties of some of the atomic transition frequencies have been reduced to the level of 10–8, the molecular transition frequencies are currently diffcult to be measured with the uncertainty below 10–15. This is mainly because of the complicated energy levels of the molecules having the vibrational-rotational states. This paper lists some molecular transition frequencies, which can be measured with the uncertainties lower than 10–16. © Anita Publications. All rights reserved.

Keywords: Precise measurement, Cold molecules, Molecular ion

Total Refs : 45

Prospect of molecular clocks
Masatoshi Kajita
National Institute of Information and Communications Technology
Koganei, Tokyo 184-8795, JAPAN
While uncertainties of some of the atomic transition frequencies have been reduced to the level of 10–8, the molecular transition frequencies are currently difficult to be measured with the uncertainty below 10–15. This is mainly because of the complicated energy levels of the molecules having the vibrational-rotational states. This paper lists some molecular transition frequencies, which can be measured with the uncertainties lower than 10–16. © Anita Publications. All rights reserved.
Prospect of molecular clocks.pdf
Masatoshi Kajita

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Asian Journal of Physics                                                                                                     Vol. 25 No 9, 2016, 1061-1068


Oscillation frequencies for simultaneous trapping of heteronuclear alkali atoms

 

Kiranpreet Kaura, B K Sahoob and Bindiya Aroraa*

aDepartment of Physics, Guru Nanak Dev University, Amritsar, Punjab-143 005, India

bTheoretical Physics Division, Physical Research Laboratory, Navrangpura, Ahemadabad-380 009, India

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We investigate oscillation frequencies for simultaneous trapping of more than one type of alkali atoms in a common optical lattice. For this purpose, we present numerical results for “magic” trapping conditions, where the oscillation frequencies for two different kinds of alkali atoms using laser lights in the wavelength range 500-1200 nm are same. These wavelengths will be of immense interest for studying static and dynamic properties of boson-boson, boson-fermion, fermion-fermion, and boson-boson-boson mixtures involving different isotopes of Li, Na, K, Rb, Cs and Fr alkali atoms. In addition to this, we were also able to locate a magic wavelength around 808.1 nm where all the three Li, K, and Rb atoms are found to be suitable for oscillating at the same frequency in a common optical trap.

Total Refs: 53

Oscillation frequencies for simultaneous trapping of heteronuclear alkali atoms.pdf
Kiranpreet Kaur, B K Sahoo and Bindiya Arora

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Asian Journal of Physics                                                                                                       Vol. 25 No 9, 2016,1069-1092


Singly charged ions for optical clocks


N Batra1,2, A Roy2, S Majhi2, S Panja1,2 and S De1,2

1Academy of Scientic and Innovative Research (AcSIR),

CSIR- National Physical Laboratory (CSIR-NPL) Campus, New Delhi, India

2CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi-110012, India.

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In modern era atomic clocks are the most accurate instruments given by the scientific community which use State-of-the-Art cooling and trapping technologies. Atomic clocks at the optical frequencies are new addition in the last one decade which provide 1s accuracy over the age of the universe. Neutral atoms in optical lattices and single ion in a Paul trap are the two well established techniques for optical frequency standards. In this article we focus on the atomic ions optical frequency standards. Recent worldwide developments, different choice of the species and associated dominant systematics have been discussed in this review. © Anita Publications. All rights reserved.

Keywords: Atomic clocks, Frequency standards, Optical frequency standards, Optical lattice, Ion trap, Systematic shifts, Precision measurement.

Total Refs: 150

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Asian Journal of Physics                                                                                                      Vol 25, No 9, 2016,1093-1101


Permanent EDM measurement in Cs using nonlinear magneto-optic rotation


Harish Ravi, Mangesh Bhattarai, Abhilash Y D, Ummal Momeen* and Vasant Natarajan

Department of Physics, Indian Institute of Science, Bangalore-560 012, India

*School of Advanced Sciences, VIT University, Vellore 632 014, India

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We use the technique of chopped nonlinear magneto-optic rotation (NMOR) at room temperature in 133Cs vapor cell to measure the permanent electric dipole moment (EDM) in the atom. The cell has paraffin coating on the walls to increase the relaxation time. The signature of the EDM is a shift in the Larmor precession frequency which is correlated with the application of an E field. We analyze errors in the technique, and show that the main source of systematic error is the appearance of a longitudinal B field when the E field is applied. This error can be eliminated by doing measurements on the two ground hyperfine levels. Using an E field of 2.6 kV/cm, we place an upper limit on the electron EDM of 2.9´10–22 e-cm (95% condence). This limit can be increased by 7 orders-of-magnitude|and brought below the current best experimental value|with easily implementable improvements to the technique. © Anita Publications. All rights reserved.

Keywords: NMOR; EDM; Paraffin coating.

Total Refs: 14

Permanent EDM measurement in Cs using nonlinear magneto-optic rotation.pdf
Harish Ravi, Mangesh Bhattarai, Abhilash Y D, Ummal Momeen and Vasant Natarajan

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Asian Journal of Physics                                                                                                       Vol 25, No 9, 2016,1103-1117

 

Precise many-electron calculations of isotope shift for alkali like atoms or ions

 

Sourav Roy1, Anal Bhowmik2 and Sonjoy Majumder2

1 Department of Chemistry, Ben Gurion University of the Negev, Beer Sheva 84105, Israel

2 Department of Physics, Indian Institute of Technology-Kharagpur, Kharagpur-721 302, India

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In this paper, we review the precise many-body calculations isotope shift for alkali and singly ionized alkaline earth atoms. Relativistic coupled cluster method is employed here to have correlation exhaustive results. We showed that the preciseness of the results not only depends on the proper consideration of excitation cluster amplitudes, but also important on exact description of Dirac-Hartree-Fock orbitals wavefunctions over the radial extent. Our results for the mass constants are also compared with the values extracted from the experimental measurements. Distinct and interesting relativistic correction of IS, magic nucleon number and even-odd staggering phenomena of nucleus are studied in terms of different isotopes. © Anita Publications. All rights reserved

Total Refs: 62

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Asian Journal of Physics                                                                                                     Vol 25, No 9, 2016,1119-1141


Energy level crossing of highly charged ions for optical clocks

 

Yan-mei Yu1  and Bing-bing Suo2

1Beijing National Laboratory for Condensed Matter Physics,

Institute of Physics, Chinese Academy of Sciences, Beijing 100190,China and

2Institute of Modern Physics, Northwest University, Xi’an, Shaanxi 710069, China

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New clock scheme based on the highly charged ions (HCIs) has been proposed for the accuracy at 10–19  recently. The key advantage of HCIs comes from their high ionic charge. The E1 transitions in HCIs are in x-ray range usually. However, near the level crossings, configuration crossing keeps frequencies of transitions in the optical range and also provides wealthy chances for looking for the relatively strong transition line for cooling. Preliminary knowledge of energy level crossings in HCIs is very useful to select suitable ions for better atomic clocks.. In this paper, a large quantity of energy level data of the HCIs are summarized in order to illustrate 3d − 4s, 4d−5s, 5d−6s, 4f −5d, 4f − 6s, 4f − 5p, and 4f − 5s crossings in isoelectronic sequences with the increasing number of electrons. The tendency of the energy level crossings that occur at the first six rows of the periodic table is reviewed. Some new HCIs near the energy level crossings are suggested that have transitions within the wavelength range accessible to modern lasers and have enriched sensitivity to potential time variation of fine structure constant. © Anita Publications. All rights reserved

Total Refs:21

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Asian Journal of Physics                                                                                                      Vol 25, No 9, 2016,1143-1159

 

The magnetic moment of the bound electron


G Werth1 and S Sturm2

1Johannes Gutenberg University, Institutfuer Physik, 55099 Mainz, Germany

2Max-Planck Institute for Nuclear Physics, Saupfercheckweg, 169117 Heidelberg, Germany

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The magnetic moments of electrons, generally expressed by the dimensionless g-factorg = ΔE/μB BΔm as scaling factor for the energy difference ΔE between Zeeman levels of quantum number m in a magnetic field B is an important quantity for our understanding of atomic structure. Penning traps are the instruments of choice to measure values of g for charged particles. We review results of measurements performed in recent years onmulti-electron ions which serve as test of atomic structure calculations. Very precise results have been obtained on hydrogen- andlithium-like ions which represent to date the most stringent test of Quantum Electrodynamic calculations in bound systems. From a combination of experimental and theoretical results we derived a new value for the electron's atomic mass, improving the number listed in the tables of fundamental constants by more than one order of magnitude.© Anita Publications. All rights reserved.

Keywords: Magnetic moment, Spin, Zeeman levels

Total Refs: 33

The magnetic moment of the bound electron.pdf
The magnetic moment of the bound electron by G Werth and S Sturm

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Asian Journal of Physics                                                                                                     Vol 25, No 9, 2016,1161-1206

 

Computational methods for high-precision spectroscopy of three-electron atomic systems


Liming Wang1, Chun Li2, and Zong-Chao Yan3

1Department of Physics,  Henan Normal University, Xinxiang, Henan, P. R. China 453007

2Department of Mathematics, Nanjing University, Nanjing, Jiangsu, P. R. China 210093

3 Department of Physics, University of New Brunswick, Fredericton, New Brunswick, Canada E3B 5A3

4Wuhan Institute of Physics and Mathematics,Chinese Academy of Sciences, Wuhan, Hubei, P. R. China 430071

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Recent progress on computational methods for high precision calculations of three-electron atomic systems are reviewed. We first introduce two important methods for solving the time independent Schrödinger equation, the Rayleigh-Ritz variational method and Rayleigh-Schrödinger perturbation method. We then show how to construct a nonrelativistic wave function variationally in Hylleraas coordinates and how to solve the eigenvalue problems of the Hamiltonian for a three-electron atomic system. We then focus on computational aspects of relativistic and quantum electrodynamic corrections to atomic energy levels. Some theoretical results for nonrelativistic energy eigenvalues, ionization energies, fine structure splittings, and isotope shifts are reviewed. Finally, we include two special sections that describe, respectively, basic mathematical properties of Schrödinger operators and mathematical theory of the Fromm-Hill integral. © Anita Publications. All rights reserved.

Keywords: Schrödinger equation; Rayleigh-Ritz variational method; Rayleigh-Schrödinger perturbation method; Hamiltonian

Total Refs:165

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Asian Journal of Physics                                                                                                      Vol 25, No 9, 2016,1207-1231


Precision measurements based on 40Ca+ ion optical frequency standards

 

Hua Guan1, 2, Yao Huang1, 2, Cheng-bin Li1, Li-yan Tang1, and Ke-lin Gao1, 2*

1State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics,

Chinese Academy of Sciences, Wuhan 430071, China [1]

2Key Laboratory of Atomic Frequency Standards, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China

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The development of the optical frequency standard based on trapped and cold 40Ca+ with the 4s 2S1/2–3d 2D5/2 clock transition at 729 nm is reported. A single 40Ca+ ion is trapped and laser cooled in a ring Paul trap, and the storage time for the ion is more than one month. The linewidth of a 729 nm laser is reduced to about 1 Hz by locking to a super cavity for longer than one month uninterruptedly. In order to realize the frequency comparison, two similar 40Ca+ optical frequency standards are established. The overall systematic uncertainties of the clock transition of two 40Ca+ optical frequency standards are evaluated to be better than 6 × 10-17. With an over-one-month measurement, the frequency difference between the two clocks is measured to be 3.2 × 10−17 with a measurement uncertainty of 5.5 × 10−17, considering both the statistic (1.9 × 10−17) and the systematic (5.1 × 10−17) uncertainties. By the frequency comparison in three days uninterruptedly, a fractional stability of 7 × 10−17 in 20 000 s of averaging time is achieved. At the same time, the absolute frequency of the clock transition is measured at 10-15 level by using an optical frequency comb referenced to a Hydrogen maser which is calibrated to the SI second through the global positioning system (GPS). The frequency value is 411042129776401.7(1.1) Hz with the correction of the systematic shifts. Moreover, additional two precision measurements based on single trapped 40Ca+ ion are carried out. One is magic wavelengths for 4s 2S1/2-3d 2D5/2 clock transition, λ|mj|=1/2 = 395.7992(7) nm and λ|mj|=3/2 = 395.7990(7) nm are measured. It’s the first time that two magic wavelengths for the 40Ca+ clock-transition are reported. And the correlation between the magic wavelengths and the polarization direction of the linearly polarized laser is preliminary studied. The other one is the 3d 2D5/2 state lifetime measurement, our result of 1174(10) ms agrees well with the experimental results reported by P. A. Barton et al. [Phys. Rev. A 62, 032503 (2000)], A. Kreuter et al. [Phys. Rev. A 71, 032504 (2005)] and the recent RCC calculation result by B. K. Sahoo [Phys. Rev. A 91, 022511 (2015)].

Total Refs : 58

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Asian Journal of Physics                                                                                                    Vol 25, No 9 (2016) 1233-1245


Precision physics with molecules


Amar C Vutha

Department of Physics, University of Toronto, 60 St. George Street, Toronto ON M5S 1A7, Canada

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Molecules have become an important resource for precisely measuring a number of fundamental physics quantities. This review provides an introduction to the properties of molecules that make them suitable for precision measurements, and surveys the state of the art in precision molecular physics experiments.© Anita Publications. All rights reserved.

Keywords: Fundamental physics quantities; Precision measurements

Total Ref: 90

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