Electron correlation plays a key role in high-temperature cuprate superconductors. Material-parameter dependence of cuprates is important to clarify the mechanism of high temperature superconductivity. In this study, ...Electron correlation plays a key role in high-temperature cuprate superconductors. Material-parameter dependence of cuprates is important to clarify the mechanism of high temperature superconductivity. In this study, we examine the ground state of the three-band Hubbard model (d-p model) that explicitly includes oxygen p orbitals. We consider the half-filled case with the large on-site Coulomb repulsion Ud by using the variational Monte Carlo method. The ground state is insulating when Ud is large at half-filling. The ground state undergoes a transition from a metal to a Mott insulator when the level difference εp-εd is increased.展开更多
Thermally activated delayed fluorescence（TADF） emitters are primarily comprised of intramolecular charge-transfer（ICT） molecules with small energy difference between the lowest singlet and triplet excited states.T...Thermally activated delayed fluorescence（TADF） emitters are primarily comprised of intramolecular charge-transfer（ICT） molecules with small energy difference between the lowest singlet and triplet excited states.They lend extremely favorable electroluminescent performance to organic light-emitting diodes（OLEDs）.This paper summarizes relevant issues and research efforts in the theoretical prediction of singlet- and triplet-transition energies of ICT molecules via time-dependent density functional theory（TDDFT）.The successful application of the descriptor-based optimal Hartree-Fock percentage method and the optimally tuned range-separated functional to many TADF systems represent an interesting approach to the exact prediction of the complex excited-state molecular dynamics within TDDFT.展开更多
文摘Electron correlation plays a key role in high-temperature cuprate superconductors. Material-parameter dependence of cuprates is important to clarify the mechanism of high temperature superconductivity. In this study, we examine the ground state of the three-band Hubbard model (d-p model) that explicitly includes oxygen p orbitals. We consider the half-filled case with the large on-site Coulomb repulsion Ud by using the variational Monte Carlo method. The ground state is insulating when Ud is large at half-filling. The ground state undergoes a transition from a metal to a Mott insulator when the level difference εp-εd is increased.
基金the Exploratory Research for Advanced Technology (ERATO) of Japanthe Key Special Program of the Ministry of Science and Technology of China(No.2016YFB0401000) for financial support
文摘Thermally activated delayed fluorescence（TADF） emitters are primarily comprised of intramolecular charge-transfer（ICT） molecules with small energy difference between the lowest singlet and triplet excited states.They lend extremely favorable electroluminescent performance to organic light-emitting diodes（OLEDs）.This paper summarizes relevant issues and research efforts in the theoretical prediction of singlet- and triplet-transition energies of ICT molecules via time-dependent density functional theory（TDDFT）.The successful application of the descriptor-based optimal Hartree-Fock percentage method and the optimally tuned range-separated functional to many TADF systems represent an interesting approach to the exact prediction of the complex excited-state molecular dynamics within TDDFT.
