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Measurement of quantum defects of nS and nD states using field ionization spectroscopy in ultracold cesium atoms 被引量:1
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作者 张临杰 冯志刚 +3 位作者 李安玲 赵建明 李昌勇 贾锁堂 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第5期1838-1842,共5页
This paper reports that ultracold atoms are populated into different nS and nD Rydberg states (n=25-52) by two-photon excitation. The ionization spectrum of an ultracold Rydberg atom is acquired in a cesium magneto-... This paper reports that ultracold atoms are populated into different nS and nD Rydberg states (n=25-52) by two-photon excitation. The ionization spectrum of an ultracold Rydberg atom is acquired in a cesium magneto-optical trap by using the method of pulse field ionization. This denotes nS and nD states in the ionization spectrum and fits the data of energy levels of different Rydberg states to obtain quantum defects of nS and nD states. 展开更多
关键词 ultracold Rydberg atoms quantum defect field ionization spectrum two-photon excitation
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An effective quantum defect theory for the diamagnetic spectrum of a barium Rydberg atom
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作者 李波 刘红平 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第1期23-26,共4页
A theoretical calculation is carried out to investigate the spectrum of a barium Rydberg atom in an external magnetic field. Using an effective approach incorporating quantum defect into the centrifugal term in the Ha... A theoretical calculation is carried out to investigate the spectrum of a barium Rydberg atom in an external magnetic field. Using an effective approach incorporating quantum defect into the centrifugal term in the Hamiltonian, we reexamine the reported spectrum of the barium Rydberg atom in a magnetic field of 2.89 T [J. Phys. B 28 L537 (1995)]. Our calculation employs B-spline basis expansion and complex coordinate rotation techniques. For single photon absorption from the ground 6s2 to 6snp Rydberg states, the spectrum is not influenced by quantum defects of channels ns and nd. The calculation is in agreement with the experimental observations until the energy reaches E = -60 cm-1. Beyond this energy, closer to the threshold, the calculated and experimental results do not agree with each other. Possible reasons for their discrepancies are discussed. Our study affirms an energy range where the diamagnetic spectrum of the barium atom can be explained thoroughly using a hydrogen model potential. 展开更多
关键词 diamagnetic spectrum quantum defect barium Rydberg atom
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Energy level analyses of even-parity J=1 and 2 Rydberg states of Sn I by multichannel quantum defect theory
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作者 由帅 凤艳艳 戴振文 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第6期2229-2237,共9页
This paper analyzes the energy levels along the even-parity J = 1 and 2 Rydberg series of Sn I by multichannel quantum defect theory. A good agreement between theoretical and experimental energy levels was achieved. B... This paper analyzes the energy levels along the even-parity J = 1 and 2 Rydberg series of Sn I by multichannel quantum defect theory. A good agreement between theoretical and experimental energy levels was achieved. Below 59198 cm^-1, a total of 85 and 23 new energy levels, respectively, in the J = 1 and J = 2 series, which cannot be measured previously by experiments, are predicted in this work. Based on the calculated admixture coefficients of each channel, interchannel interactions were discussed in detail. The results are helpful to understand the characteristics of configuration interaction among even-parity levels in Sn I. 展开更多
关键词 atom Sn Rydberg state multichannel quantum defect theory
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Exact quantum defect theory approach for lithium in magnetic fields
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作者 徐家坤 陈海清 刘红平 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第1期183-186,共4页
We calculate the diamagnetic spectrum of lithium at highly excited states up to the positive energy range using the exact quantum defect theory approach. The concerned excitation is one-photon transition from the grou... We calculate the diamagnetic spectrum of lithium at highly excited states up to the positive energy range using the exact quantum defect theory approach. The concerned excitation is one-photon transition from the ground state 2s to the highly excited states np with π and σ polarizations respectively. Lithium has a small quantum defect value 0.05 for the np states, and its diamagnetic spectrum is very similar to that of hydrogen in the energy range approaching the ionization limit. However, a careful calculation shows that the spectrum has a significant discrepancy with that of hydrogen when the energy is lower than -70 cm-1. The effect of the quantum defect is also discussed for the Stark spectrum. It is found that the σ transition to the np states in an electric field has a similar behavior to that of hydrogen due to zero interaction with channel ns. 展开更多
关键词 diamagnetic spectrum quantum defect theory
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Building Wave Functions of the Outer Electron for Alkaline Atoms Theory and Wave Functions Representation
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作者 Amaury de Kertanguy 《Journal of Applied Mathematics and Physics》 2020年第11期2601-2612,共12页
The effects of the polarization potential serve to model spectra of alkaline atoms. These effects have been known for a long time and notably explained by the physicist Max Born (1926). The experimental knowledge of t... The effects of the polarization potential serve to model spectra of alkaline atoms. These effects have been known for a long time and notably explained by the physicist Max Born (1926). The experimental knowledge of these alkaline spectra enables us to specify the values of these quantum defects. A simple code is used to calculate two quantum defects for which <em>δ<sub>l</sub></em><sub> </sub>can be distinguished as: <em>δ<sub>s</sub></em> <em>l</em> = 0 and <em>δ<sub>p</sub></em> <em>l</em> = 1. On the theoretical part, it is possible to have an analytical expression for these quantum defects <em>δ<sub>l</sub></em>. A second code gives the correct wave functions modified by the quantum defects <em>δ<sub>l</sub></em> with the condition for the principal number: <em>n</em><sub><span style="white-space:nowrap;"><span style="white-space:nowrap;">*</span></span></sub> = <em>n</em> – <em>δ</em><sub><em>l</em></sub> ≥ 1. It is well known that <em>δ</em><sub><em>l</em></sub> → 0 when the kinetic momentum <em>l</em> ≥ 4, and for such momenta the spectra turns out to be hydrogenic. Modern software such as Mathematica, allows us to efficiently generate the polynomes defining wave functions with fractional quantum numbers. This leads to a good theoretical representation of these wave functions. To get numerically the quantum defects, a simple code is given to obtain these quantities when the levels assigned to a transition are known. Then, the quantum defects are inserted into the arguments of the correct modified wave functions for the outer electron of an atom or ion undergoing the short range polarization potential. 展开更多
关键词 Polarization Potential Experimental quantum defects quantum Wave Functions Mathematica Software
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Transition energy and dipole oscillator strength for 1s^22p-1s^2nd of Cr^(21+) ion 被引量:7
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作者 王治文 刘影 +2 位作者 胡木宏 李新汝 王亚男 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第8期2909-2913,共5页
The transition energies, wavelengths and dipole oscillator strengths of 1s^22p-1s^2nd (3 ≤ n ≤ 9) for Cr^21+ ion are calculated. The fine structure splittings of 1s^2nd (n ≤ 9) states for this ion are also cal... The transition energies, wavelengths and dipole oscillator strengths of 1s^22p-1s^2nd (3 ≤ n ≤ 9) for Cr^21+ ion are calculated. The fine structure splittings of 1s^2nd (n ≤ 9) states for this ion are also calculated. In calculating energy, we have estimated the higher-order relativistic contribution under a hydrogenic approximation. The quantum defect of Rydberg series 1s^2nd is determined according to the quantum defect theory. The results obtained in this paper excellently agree with the experimental data available in the literature. Combining the quantum defect theory with the discrete oscillator strengths, the discrete oscillator strengths for the transitions from initial state 1s^22p to highly excited 1s^2nd states (n ≥ 10) and the oscillator strength density corresponding to the bound-free transitions are obtained. 展开更多
关键词 Cr^21+ ion transition energy fine structure splitting quantum defect
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Energy levels of 1s^2n d(n≤9)states for lithium-like ions 被引量:3
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作者 胡木宏 王治文 +2 位作者 曾凡伟 王涛 王晶 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第8期169-175,共7页
The full-core plus correlation method with multi-configuration interaction wave functions is extended to the calcu- lation of the non-relativistic energies of ls2nd (n ≤9) states for the lithium isoelectronic seque... The full-core plus correlation method with multi-configuration interaction wave functions is extended to the calcu- lation of the non-relativistic energies of ls2nd (n ≤9) states for the lithium isoelectronic sequence from Z = 11 to 20. Relativistic and mass-polarization effects on the energy are calculated as the first-order perturbation correction. The quantum-electrodynamics correction is also included. The fine structure splittings are determined from the expectation values of spin-orbit and spin-other-orbit interaction operators in the Pauli-Breit approximation. Combining the term energies of lowly excited states obtained with the quantum defects calculated by the single channel quantum defect theory, each of which is a smooth function of energy and approximated by a weakly varying function of energy, the ion potentials of highly excited states (n ≥ 6) are obtained with the semi-empirical iteration method. The results are compared with experimental data in the literature and found to be closely consistent with the regularity. 展开更多
关键词 lithium-like ions excited states quantum defect theory quantum defect
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Behaviours of the excited states 1s^2 np along lithium isoelectronic sequence from Z=11 to 20 被引量:3
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作者 胡木宏 王治文 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第3期908-914,共7页
Based on the obtained energy values of 1s^2np (n≤ 9) states for lithium-like systems from Z=11 to 20 (by the authors of this paper: Hu M H and Wang Z W 2004 Chin. Phys. 13 662), this paper determines the quantum... Based on the obtained energy values of 1s^2np (n≤ 9) states for lithium-like systems from Z=11 to 20 (by the authors of this paper: Hu M H and Wang Z W 2004 Chin. Phys. 13 662), this paper determines the quantum defects, as slowly varying function of energy, of this Rydberg series. Using them as input, it can predict the energies of any highly excited states below the ionization threshold for this series a^cording to the quantum defect theory. The regularities of variation for quantum defects of the series along this isoelectronic sequence are physically analysed and discussed. The screening parameters, which are equal to the effective screening charge of the core-electrons, are also obtained. 展开更多
关键词 lithium-like system excited state quantum defect screening parameter
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Oscillator strengths for 2 ~2S-n^2P transitions of the lithium isoelectronic sequence from Z=11 to 20 被引量:2
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作者 胡木宏 王治文 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第6期2244-2249,共6页
The dipole-length, dipole-velocity and dipole-acceleration absorption oscillator strengths for the 1s^22s-1s^2np (3 ≤ n ≤9) transitions of lithium-like systems from Z = 11 to 20 are calculated by using the energie... The dipole-length, dipole-velocity and dipole-acceleration absorption oscillator strengths for the 1s^22s-1s^2np (3 ≤ n ≤9) transitions of lithium-like systems from Z = 11 to 20 are calculated by using the energies and the multiconfiguration interaction wave functions obtained from a full core plus correlation method, in which relativistic and mass-polarization effects on the energy, as the first-order perturbation corrections, are included. The results of three forms are in good agreement with each other, and closely agree with the experimental data available in the literature. Based on the quantum defects obtained with quantum defect theory (QDT), the discrete oscillator strengths for the transitions from the ground state to highly excited states 1s^2np (n ≥ 10) and oscillator strength densities corresponding to the bound-free transitions are obtained for these ions. 展开更多
关键词 lithium isoelectronic sequence oscillator strengths quantum defect
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Non-linear spectral splitting of Rydberg sodium in external fields 被引量:1
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作者 高伟 杨海峰 +3 位作者 成红 张珊珊 刘丹峰 刘红平 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第1期216-220,共5页
We have studied highly excited sodium in various electric fields, parallel electric and magnetic fields, with one σ andπ photon irradiation, and even in a magnetic field with a complex laser polarization configurati... We have studied highly excited sodium in various electric fields, parallel electric and magnetic fields, with one σ andπ photon irradiation, and even in a magnetic field with a complex laser polarization configuration. The σ spectra shows a simple linear Stark effect with the applied electric field, while the π spectra exhibits a strong non-linear dependence on the electric field. The π transitions in parallel fields show a similar behavior to that in a pure electric field but the spectra get more smooth due to the magnetic field. The diamagnetic spectrum with laser polarization angles between 0 and π /2 proves that it can be reproduced by simple linear combination of π and σ components, indicating there is no interference between the π and σ channels. A full quantum calculation considering the quantum defects accounts for all the observations. The quantum defects, especially for the channel np, play an important role in the spectral profile. 展开更多
关键词 Stark spectrum magnetic spectrum quantum defect
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Heat transport in low-dimensional materials: A review and perspective 被引量:1
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作者 Zhiping Xu 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2016年第3期113-121,共9页
Heat transport is a key energetic process in materials and devices. The reduced sample size, low dimension of the problem and the rich spectrum of material imperfections introduce fruitful phenomena at nanoscale. In t... Heat transport is a key energetic process in materials and devices. The reduced sample size, low dimension of the problem and the rich spectrum of material imperfections introduce fruitful phenomena at nanoscale. In this review, we summarize recent progresses in the understanding of heat transport process in low-dimensional materials, with focus on the roles of defects, disorder, interfaces, and the quantum- mechanical effect. New physics uncovered from computational simulations, experimental studies, and predictable models will be reviewed, followed by a perspective on open challenges. 展开更多
关键词 Nanoscale heat transport Low-dimensional materials defects Disorder Interfaces quantum mechanical effects
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Photoionization Study of the 2s^(2)2p^(2)(^(1)D)ns(^(2)D),2s^(2)2p^(2)(^(1)D)nd(^(2)P),2s^(2)2p^(2)(^(1)D)nd(^(2)S),2s^(2)2p^(2)(^(1)S)nd^(2)D,and 2s^(2)2p^(3)(^(3)P)np(^(2)D)Rydberg Series of O+Ions via the Modified Atomic Orbital Theory 被引量:1
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作者 Malick Sow Fatou Ndoye +4 位作者 Alassane Traoré Abdou Diouf Boubacar Sow Youssou Gning Papa Amadou Lamine Diagne 《Journal of Modern Physics》 2021年第10期1435-1446,共12页
We report in this paper energy positions of the 2P˚_2s^(2)2p^(2)(^(1)D)nd 2P,2P˚_2s^(2)2p^(2)(^(1)D)nd 2S,2P˚_2s^(2)2p^(2)(^(1)D)ns^(2)D,2P˚_2s^(2)2p^(2)(^(1)S)nd ^(2)D,and 2P˚_2s^(2)2p^(3)(^(3)P)np ^(2)D Rydberg seri... We report in this paper energy positions of the 2P˚_2s^(2)2p^(2)(^(1)D)nd 2P,2P˚_2s^(2)2p^(2)(^(1)D)nd 2S,2P˚_2s^(2)2p^(2)(^(1)D)ns^(2)D,2P˚_2s^(2)2p^(2)(^(1)S)nd ^(2)D,and 2P˚_2s^(2)2p^(3)(^(3)P)np ^(2)D Rydberg series in the photoionization spectra originating from 2P˚metastable state of O+ions.Calculations are performed up to n=30 using the Modified Orbital Atomic Theory(MAOT).The present results are compared to the experimental data of Aguilar which are the only available values.The accurate data presented in this work may be a useful guideline for future experimental and other theoretical studies. 展开更多
关键词 Semiempirical Calculations Modified Orbital Atomic Theory Electron Correlation Calculations Atoms and Ions Rydberg Series quantum Defect
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Theoretical study on 2s2p^6np Rydberg states of Cu^(19+)ion
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作者 Zhang Zhen-Rong Cheng Xin-Lu +2 位作者 Liu Zi-Jiang Yang Jian-Hui Li Hui-Fang 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第1期153-157,共5页
We report on the calculations of transition wavelengths and weighted oscillator strengths for 2s22p^6 2s2p^6np (4 〈 n 〈 20) electric dipole (El) transitions of Cu^19+ ion. The flexible atomic code (FAC) has b... We report on the calculations of transition wavelengths and weighted oscillator strengths for 2s22p^6 2s2p^6np (4 〈 n 〈 20) electric dipole (El) transitions of Cu^19+ ion. The flexible atomic code (FAC) has been adopted for the calculations. Comparisons are made with the experimental data available, showing that the present results for 4 〈 n 〈 6 are more accurate than the previous calculated values. Furthermore, combining the quantum defect theory (QDT) with the transition energies of 2s^22p^62s2p^6np, the quantum defects for 2s2p^6np Rydberg series of Cu^19+ ion are determined. In addition, the energies of any highly excited states (n 〉 20) for this series can be reliably predicted using the QDT and the given quantum defects. The ionization energies for Cu^19+ and Cu^20+ ions are also calculated and they excellently accord with previous experimental and calculated values. 展开更多
关键词 Cu^19+ion transition wavelength quantum defect quantum defect theory
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Theoretical analysis of ionic autoionization spectra of lanthanum via an intermediate state [Xe]5d6d 1P1
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作者 仲银鹏 贾凤东 钟志萍 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第10期4242-4250,共9页
In the framework of multi-channel quantum defect theory, eigenquantum defects μα and the transformation matrices Uiα of La+ are calculated from first principles by relativistic multi-channel theory, while the dipo... In the framework of multi-channel quantum defect theory, eigenquantum defects μα and the transformation matrices Uiα of La+ are calculated from first principles by relativistic multi-channel theory, while the dipole matrix elements DCr are obtained by fitting with experimental data. Then the ionic autoionization spectra of lanthanum via the intermediate state [Xe]5d6d 1p1 in the energy region of 90213-91905 cm-1 axe obtained. Experimental peaks are classified and assigned by comparing with the corresponding calculated spectra. More specifically, four ionic autoionization Rydberg series converging to La2+ 5d5/2 2D5/2 and several states converging to higher lying states of La2+ are found and assigned. 展开更多
关键词 configuration interaction multi-channel quantum defect theory relativistic multichannel theory autoionization Rydberg series
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Relativistic multichannel treatment of autoionization Rydberg series of 4s^2nf(n=4-23)J~π=(7/2)° for scandium
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作者 贾凤东 王京阳 钟志萍 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第6期2027-2032,共6页
Based on relativistic multichannel theory, this paper calculates the energy levels of autoionization Rydberg series 4s^2nf(n=4- 23)J^π -(7/2)° of scandium at different levels of approximation within the fram... Based on relativistic multichannel theory, this paper calculates the energy levels of autoionization Rydberg series 4s^2nf(n=4- 23)J^π -(7/2)° of scandium at different levels of approximation within the framework of multichannel quantum defect theory. The present results show that the dipole polarizations play an important role. Considering the dynamical dipole polarization effects, this paper finds that the difference between calculated and experimental quantum defects for the 4s^2nf(n=4- 23)J^π -(7/2)° series is generally about 0.01- 0.03. Furthermore, the reason that 4s^216f is obscured in experimental spectra is suggested to be the interaction with the neighbouring resonance state converged to 3d^2(^1G4) of Sc^+. 展开更多
关键词 relativistic multichannel theory multichannel quantum defect theory electron-electron correlations
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Modified Atomic Orbital Theory of the O+ Ion Originating from 2D0 and 4S0 Metastable States
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作者 Malick Sow Fatou Ndoye +3 位作者 Babou Diop Alassane Traoré Abdou Diouf Boubacar Sow 《Journal of Applied Mathematics and Physics》 2022年第6期1873-1886,共14页
We report in this paper energy positions of the 2D<sup>0</sup>_2s<sup>2</sup>2p<sup>2</sup>(<sup>1</sup>D)nd(<sup>2</sup>F);2D<sup>0</sup>_2s<... We report in this paper energy positions of the 2D<sup>0</sup>_2s<sup>2</sup>2p<sup>2</sup>(<sup>1</sup>D)nd(<sup>2</sup>F);2D<sup>0</sup>_2s<sup>2</sup>2p<sup>2</sup>(<sup>1</sup>D)nd(<sup>2</sup>D);2D<sup>0</sup>_2s<sup>2</sup>2p<sup>2</sup>(<sup>1</sup>D)nd(<sup>2</sup>P);2D<sup>0</sup>_2s<sup>2</sup>2p<sup>2</sup>(<sup>1</sup>D)ns(<sup>2</sup>D);2D<sup>0</sup>_2s<sup>2</sup>2p<sup>3</sup>(<sup>3</sup>D)np(<sup>2</sup>P);2D<sup>0</sup>_2s<sup>2</sup>2p<sup>3</sup>(<sup>3</sup>D<sup>0</sup>)np(<sup>2</sup>F), and 4S<sup>0</sup>_2s<sup>2</sup>2p<sup>3</sup>(<sup>5</sup>S<sup>0</sup>)np(<sup>4</sup>P) Rydberg series in the photoionization spectra originating from 2D<sup>0</sup> and 4S<sup>0</sup> metastable states of O<sup>+</sup> ion. Calculations are performed up to n = 20 using the Modified Orbital Atomic Theory (MAOT) [1]. The present results are compared to the experimental data of Aguilar et al. [2] which are the only available values. The accurate data presented in this work may be a useful guideline for future experimental and other theoretical studies. 展开更多
关键词 Semiempirical Calculations Modified Orbital Atomic Theory Electron Correlation Calculations Atoms and Ions Rydberg Series quantum Defect
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