High-quality Bi2-xPbxSr2 CaCu2O8+δ(Bi2212) single crystals have been successfully grown by the traveling solvent floating zone technique with a wide range of Pb substitution(x = 0–0.8).The samples are characterized ...High-quality Bi2-xPbxSr2 CaCu2O8+δ(Bi2212) single crystals have been successfully grown by the traveling solvent floating zone technique with a wide range of Pb substitution(x = 0–0.8).The samples are characterized by transmission electron microscope(TEM) and measured by high resolution laser-based angle-resolved photoemission spectroscopy(ARPES) with different photon energies.A systematic evolution of the electronic structure and superstructure with Pb substitution has been revealed for the first time.The superstructure shows a significant change with Pb substitution and the incommensurate modulation vector(Q) decreases with increasing Pb substitution.In the meantime, the superstructure intensity from ARPES measurements also decreases dramatically with increasing Pb concentration.The superstructure in Bi2212 can be effectively suppressed by Pb substitution and it nearly disappears with a Pb substitution of x = 0.8.We also find that the superstructure bands in ARPES measurements depend sensitively on the photon energy of lasers used;they can become even stronger than the main band when using a laser photon energy of 10.897 eV.These results provide important information on the origin of the incommensurate superstructure and its control and suppression in bismuth-based high temperature superconductors.展开更多
We investigate the chaotic dynamics of normal mode molecules from the classical point of view using the coupling Morse oscillators.New interesting phenomena of the fractured tori and the cross of tori on the poincar...We investigate the chaotic dynamics of normal mode molecules from the classical point of view using the coupling Morse oscillators.New interesting phenomena of the fractured tori and the cross of tori on the poincaré section,which go against our traditional understanding,are found and investigated.Also,we find that the phenomenon of tori cross is a siggature of the single bond's energy beyond the total vibrational energy.Finally,a method to improve this scarcity is proposed.展开更多
Quantum dynamical calculations for the IR-multiphoton excitation of H_2O,D_2O and T_2O are presented using a generalized Hamiltonian for XY_2 molecules.The energy spectra obtained from this Hamiltonian are in good agr...Quantum dynamical calculations for the IR-multiphoton excitation of H_2O,D_2O and T_2O are presented using a generalized Hamiltonian for XY_2 molecules.The energy spectra obtained from this Hamiltonian are in good agreement with those of the experiments.The long time average of the transition probabilities and the isotopic effects are discussed in detail,展开更多
The multiphoton rotation-vibration energy absorption of diatomic molecules in infrared laser fields is analytically studied using the algebraic approach.The analytical expression of the rotation-vibration transition p...The multiphoton rotation-vibration energy absorption of diatomic molecules in infrared laser fields is analytically studied using the algebraic approach.The analytical expression of the rotation-vibration transition probability is given.The long-time average absorbed energy spectra and the average number of photons absorbed by the molecule are discussed.The results show that both molecular orientation and molecular anharmonicity are important factors in the rotation-vibration multiphoton absorption.展开更多
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2016YFA0300300 and 2017YFA0302900)the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(Grant Nos.XDB07020300 and XDB25000000)+1 种基金the National Natural Science Foundation of China(Grant Nos.11334010 and 11534007)the Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.2017013)
文摘High-quality Bi2-xPbxSr2 CaCu2O8+δ(Bi2212) single crystals have been successfully grown by the traveling solvent floating zone technique with a wide range of Pb substitution(x = 0–0.8).The samples are characterized by transmission electron microscope(TEM) and measured by high resolution laser-based angle-resolved photoemission spectroscopy(ARPES) with different photon energies.A systematic evolution of the electronic structure and superstructure with Pb substitution has been revealed for the first time.The superstructure shows a significant change with Pb substitution and the incommensurate modulation vector(Q) decreases with increasing Pb substitution.In the meantime, the superstructure intensity from ARPES measurements also decreases dramatically with increasing Pb concentration.The superstructure in Bi2212 can be effectively suppressed by Pb substitution and it nearly disappears with a Pb substitution of x = 0.8.We also find that the superstructure bands in ARPES measurements depend sensitively on the photon energy of lasers used;they can become even stronger than the main band when using a laser photon energy of 10.897 eV.These results provide important information on the origin of the incommensurate superstructure and its control and suppression in bismuth-based high temperature superconductors.
基金Supported by the National Natural Science Foundation of China under Grant Nos 91021009 and 10874102.
文摘We investigate the chaotic dynamics of normal mode molecules from the classical point of view using the coupling Morse oscillators.New interesting phenomena of the fractured tori and the cross of tori on the poincaré section,which go against our traditional understanding,are found and investigated.Also,we find that the phenomenon of tori cross is a siggature of the single bond's energy beyond the total vibrational energy.Finally,a method to improve this scarcity is proposed.
文摘Quantum dynamical calculations for the IR-multiphoton excitation of H_2O,D_2O and T_2O are presented using a generalized Hamiltonian for XY_2 molecules.The energy spectra obtained from this Hamiltonian are in good agreement with those of the experiments.The long time average of the transition probabilities and the isotopic effects are discussed in detail,
基金by the National Natural Science Foundation of China under Grant Nos 10874102 and 10947103the Foundation for Outstanding Young Scientist in Shandong Province(No 2008BS01017).
文摘The multiphoton rotation-vibration energy absorption of diatomic molecules in infrared laser fields is analytically studied using the algebraic approach.The analytical expression of the rotation-vibration transition probability is given.The long-time average absorbed energy spectra and the average number of photons absorbed by the molecule are discussed.The results show that both molecular orientation and molecular anharmonicity are important factors in the rotation-vibration multiphoton absorption.