Recently, molecular electronics has become increasingly important. By applying the hybrid density functional theory coupled with the Green＇s function method, the current-voltage characteristics of the molecular junct...Recently, molecular electronics has become increasingly important. By applying the hybrid density functional theory coupled with the Green＇s function method, the current-voltage characteristics of the molecular junctions composed of gold-porphyrin-gold and gold-copper porphyrin-gold were investigated. The role of the metal coordination effect in organic molecular electron transport was highlighted. Although the thresholds of the bias voltage for both molecules were almost the same, approximately 0. 9 V, the metal compound showed a larger increase in current because of the metal-coordination-enhanced molecule-electrode coupling in the frontier molecular orbitals.展开更多
We study the ground state property of the one-dimensional Bose–Hubbard model using an imaginary time evolving body decimation algorithm.The single-particle density matrix is numerically calculated for a Mott insulati...We study the ground state property of the one-dimensional Bose–Hubbard model using an imaginary time evolving body decimation algorithm.The single-particle density matrix is numerically calculated for a Mott insulating system and a superfluid system separately.By plotting the chemical potential versus the filling n=N/L for U/J=20 and U/J=0.1,we identify the Mott gap for U/J=20 in filling n=1.Lastly,we investigate the occupation number of the Bloch state with quasimomentum for a system deep in the Mott phase and in the superfluid phase respectively.The results indicate Bose condensation in the quasimomentum space.展开更多
We present a study on the Jahn–Teller(JT)distortions of the TiO_(6),NiO_(6)and MnO_(6)complexes in NaTiO_(2),NaNiO_(2)and NaMnO_(2)triangular compounds with a C_(2)/m structure.The JT vibronic normal modes are found ...We present a study on the Jahn–Teller(JT)distortions of the TiO_(6),NiO_(6)and MnO_(6)complexes in NaTiO_(2),NaNiO_(2)and NaMnO_(2)triangular compounds with a C_(2)/m structure.The JT vibronic normal modes are found to be Q3,Q'4 and Q6 by the group symmetry on the C2/m structure.The magnitude of the normal coordinates(Q3,Q'4,Q6)and the structural parameters of distorted octahedra MO_(6)(M=Ti,Ni,Mn)are obtained and in good agreement with experimental data.The energy level splitting of 3d orbitals and the highest occupied molecular orbital(HOMO)character in the MO_(6)complex are also calculated in accordance with the JT distortions.These results provide a first insight into the groundstate and magnetic properties of distorted triangular compounds AMO_(2).展开更多
基金Supported by the National Natural Science Foundation of China(Nos 90301001 and 10425420) and the Supercomputing Center of the Chinese Academy of Sciences
文摘Recently, molecular electronics has become increasingly important. By applying the hybrid density functional theory coupled with the Green＇s function method, the current-voltage characteristics of the molecular junctions composed of gold-porphyrin-gold and gold-copper porphyrin-gold were investigated. The role of the metal coordination effect in organic molecular electron transport was highlighted. Although the thresholds of the bias voltage for both molecules were almost the same, approximately 0. 9 V, the metal compound showed a larger increase in current because of the metal-coordination-enhanced molecule-electrode coupling in the frontier molecular orbitals.
基金Supported by the National Natural Science Foundation of China under Grant No 11174100.
文摘We study the ground state property of the one-dimensional Bose–Hubbard model using an imaginary time evolving body decimation algorithm.The single-particle density matrix is numerically calculated for a Mott insulating system and a superfluid system separately.By plotting the chemical potential versus the filling n=N/L for U/J=20 and U/J=0.1,we identify the Mott gap for U/J=20 in filling n=1.Lastly,we investigate the occupation number of the Bloch state with quasimomentum for a system deep in the Mott phase and in the superfluid phase respectively.The results indicate Bose condensation in the quasimomentum space.
基金by the National Natural Science Foundation of China under Grant No 10874186the Knowledge Innovation Project of the Chinese Academy of Sciences.
文摘We present a study on the Jahn–Teller(JT)distortions of the TiO_(6),NiO_(6)and MnO_(6)complexes in NaTiO_(2),NaNiO_(2)and NaMnO_(2)triangular compounds with a C_(2)/m structure.The JT vibronic normal modes are found to be Q3,Q'4 and Q6 by the group symmetry on the C2/m structure.The magnitude of the normal coordinates(Q3,Q'4,Q6)and the structural parameters of distorted octahedra MO_(6)(M=Ti,Ni,Mn)are obtained and in good agreement with experimental data.The energy level splitting of 3d orbitals and the highest occupied molecular orbital(HOMO)character in the MO_(6)complex are also calculated in accordance with the JT distortions.These results provide a first insight into the groundstate and magnetic properties of distorted triangular compounds AMO_(2).
