We study the role of Franck-Condon(F-C) principle in the dynamics of a central spin system, which is coupled to an Ising chain in transverse field. The transition process of energy levels caused by the excited central...We study the role of Franck-Condon(F-C) principle in the dynamics of a central spin system, which is coupled to an Ising chain in transverse field. The transition process of energy levels caused by the excited central spin is studied to manifest the quantum critical effect through the Franck-Condon principle. The super-sensitivity of this quantum critical system is demonstrated clearly from the properties of Franck-Condon factors. We analytically show how spin numbers, coupling strength and order parameter of the Ising chain sensitively effect on the energy level populations in dynamical evolution near the critical point. This super-sensitivity and criticality are explicitly displayed in absorption spectrum.展开更多
Magnesium monofluoride(MgF)is proposed as an ideal candidate radical for direct laser cooling.Here,the rotationally resolved laser spectra of MgF for the A^(2)Π-X^(2)∑^(+) electronic transition system were recorded ...Magnesium monofluoride(MgF)is proposed as an ideal candidate radical for direct laser cooling.Here,the rotationally resolved laser spectra of MgF for the A^(2)Π-X^(2)∑^(+) electronic transition system were recorded by using laser induced fluorescence technique.The MgF radicals were produced by discharging SF_(6)/Ar gas mixtures between the tips of two magnesium needles in a supersonic jet expansion.We recorded a total of 19 vibrational bands belonging to three sequences of Δv=0,±1 in the region of 348-370 nm.Accurate spectroscopic constants for both X^(2)∑^(+) and A^(2)Π states are determined from rotational analysis of the experimental spectra.Spectroscopic parameters,including the Franck-Condon factors(FCFs),are determined from the experimental results and the Rydberg-Klein-Rees(RKR)calculations.Significant discrepancies between the experimentally measured and RKR-calculated FCFs are found,indicating that the FCFs are nearly independent of the spin-orbit coupling in the A^(2)Π state.Potential energy curves(PECs)and FCFs determined here provide necessary data for the theoretical simulation of the laser-cooling scheme of MgF.展开更多
We measure the dispersed spectrum of the A2H-X2E＋ system of MgH using laser abla- tion/laser induced Fluorescence method and obtain the Frank-Condon factors and related transition frequencies of the A2H（v＇=0）-X2...We measure the dispersed spectrum of the A2H-X2E＋ system of MgH using laser abla- tion/laser induced Fluorescence method and obtain the Frank-Condon factors and related transition frequencies of the A2H（v＇=0）-X2∑＋（v＂=0,1） system by analyzing the experimental spectrum. Also, we calculate the Franck-Condon factors and transition frequencies of the A2H-X2∑＋ system of MgH. A comparison of our theoretical calculation and experimental results with other reported theoretical results was carried out as well.展开更多
基金Supported by the National Basic Research Program of China under Grant Nos.2016YFA0301201 and 2014CB921403,NSFC under Grant No.11534002 and NSAF under Grant Nos.U1730449 and U1530401
文摘We study the role of Franck-Condon(F-C) principle in the dynamics of a central spin system, which is coupled to an Ising chain in transverse field. The transition process of energy levels caused by the excited central spin is studied to manifest the quantum critical effect through the Franck-Condon principle. The super-sensitivity of this quantum critical system is demonstrated clearly from the properties of Franck-Condon factors. We analytically show how spin numbers, coupling strength and order parameter of the Ising chain sensitively effect on the energy level populations in dynamical evolution near the critical point. This super-sensitivity and criticality are explicitly displayed in absorption spectrum.
基金supports from the National Natural Science Foundation of China(No.21773221 and No.21827804)the National Key R&D Program of China(No.2017YFA0303502)the Fundamental Research Funds for the Central Universities of China(No.WK2340000078)。
文摘Magnesium monofluoride(MgF)is proposed as an ideal candidate radical for direct laser cooling.Here,the rotationally resolved laser spectra of MgF for the A^(2)Π-X^(2)∑^(+) electronic transition system were recorded by using laser induced fluorescence technique.The MgF radicals were produced by discharging SF_(6)/Ar gas mixtures between the tips of two magnesium needles in a supersonic jet expansion.We recorded a total of 19 vibrational bands belonging to three sequences of Δv=0,±1 in the region of 348-370 nm.Accurate spectroscopic constants for both X^(2)∑^(+) and A^(2)Π states are determined from rotational analysis of the experimental spectra.Spectroscopic parameters,including the Franck-Condon factors(FCFs),are determined from the experimental results and the Rydberg-Klein-Rees(RKR)calculations.Significant discrepancies between the experimentally measured and RKR-calculated FCFs are found,indicating that the FCFs are nearly independent of the spin-orbit coupling in the A^(2)Π state.Potential energy curves(PECs)and FCFs determined here provide necessary data for the theoretical simulation of the laser-cooling scheme of MgF.
基金This work was supported by the National Nature Science Foundation of China （No.61205198, No.11105052） and the Fundamental Research Fhnds for the Central Universities. The authors thank Chao Hang from State Key Laboratory of Precision Spectroscopy, East China Normal University and Timothy Steimles from Chemistry and Biochemistry Department, Arizona State University for the discussion.
文摘We measure the dispersed spectrum of the A2H-X2E＋ system of MgH using laser abla- tion/laser induced Fluorescence method and obtain the Frank-Condon factors and related transition frequencies of the A2H（v＇=0）-X2∑＋（v＂=0,1） system by analyzing the experimental spectrum. Also, we calculate the Franck-Condon factors and transition frequencies of the A2H-X2∑＋ system of MgH. A comparison of our theoretical calculation and experimental results with other reported theoretical results was carried out as well.
