By using density matrix renormalization group (DMRG) method a model for organic molecule-based ferromagnetic chain is proposed. It is found that the ground states of undoped and doped systems both exhibit ferrimagneti...By using density matrix renormalization group (DMRG) method a model for organic molecule-based ferromagnetic chain is proposed. It is found that the ground states of undoped and doped systems both exhibit ferrimagnetic ordering. The e-e repulsion plays an important role in the stability of the ferromagnetic state either in doped system or undoped system. For the undoped system, each unit cell contains half of the total spins, which is consistent with Lieb's theorem. It is convinced that when the system is doped with one electron, a charge density wave is excited, which decreases the amplitude of spin density wave, therefore acting against the stability of ferromagnetic state.展开更多
运用有限系统密度矩阵重整化群算法(FS-DMRG),研究拓展Bose-Hubbard模型(即在标准BoseHubbard模型的基础上加入最近邻格点间的粒子相互排斥作用V)发生相变的特征。通过计算系统的局域粒子数密度、单粒子能隙以及压缩系数,分析了系统在...运用有限系统密度矩阵重整化群算法(FS-DMRG),研究拓展Bose-Hubbard模型(即在标准BoseHubbard模型的基础上加入最近邻格点间的粒子相互排斥作用V)发生相变的特征。通过计算系统的局域粒子数密度、单粒子能隙以及压缩系数,分析了系统在不同状态下的特征,得到了不同于标准Bose-Hubbard模型的新量子态——Charge Density Wave(CDW)态。通过分析产生特殊粒子分布方式的原因及其物理性质,得出了发生相变的临界条件。展开更多
The empirical valence bond model, solved by the DMRG technique, is applied to the systematical study of the photochemical processes of carotenoids. The polyenes with five up to one hundred of C== C bonds are investiga...The empirical valence bond model, solved by the DMRG technique, is applied to the systematical study of the photochemical processes of carotenoids. The polyenes with five up to one hundred of C== C bonds are investigated. The probability of the state arrangement for the conjugated bond, Pij, is evaluated. It is a parameter to correlate the bond lengths, and could also be applied to rationalizing the quantum yields of the photo-isomerization and the reaction constant of the quenching of singlet-oxygen happened to the external C== C bond of the carotenoids. The maximum reaction constant in long chain limit is determined as about 2.92×1010 L·mol-1·s-1.展开更多
基金the National Natural Science Foundation of China under
文摘By using density matrix renormalization group (DMRG) method a model for organic molecule-based ferromagnetic chain is proposed. It is found that the ground states of undoped and doped systems both exhibit ferrimagnetic ordering. The e-e repulsion plays an important role in the stability of the ferromagnetic state either in doped system or undoped system. For the undoped system, each unit cell contains half of the total spins, which is consistent with Lieb's theorem. It is convinced that when the system is doped with one electron, a charge density wave is excited, which decreases the amplitude of spin density wave, therefore acting against the stability of ferromagnetic state.
文摘运用有限系统密度矩阵重整化群算法(FS-DMRG),研究拓展Bose-Hubbard模型(即在标准BoseHubbard模型的基础上加入最近邻格点间的粒子相互排斥作用V)发生相变的特征。通过计算系统的局域粒子数密度、单粒子能隙以及压缩系数,分析了系统在不同状态下的特征,得到了不同于标准Bose-Hubbard模型的新量子态——Charge Density Wave(CDW)态。通过分析产生特殊粒子分布方式的原因及其物理性质,得出了发生相变的临界条件。
基金Part of the computational work was done on the SGI Origin 3800 and Dawning 3000 supercom-puters at Nanjing University. This work was supported by the National Natural Science Foundation of China (Grant Nos. 20073020 and 20273030).
文摘The empirical valence bond model, solved by the DMRG technique, is applied to the systematical study of the photochemical processes of carotenoids. The polyenes with five up to one hundred of C== C bonds are investigated. The probability of the state arrangement for the conjugated bond, Pij, is evaluated. It is a parameter to correlate the bond lengths, and could also be applied to rationalizing the quantum yields of the photo-isomerization and the reaction constant of the quenching of singlet-oxygen happened to the external C== C bond of the carotenoids. The maximum reaction constant in long chain limit is determined as about 2.92×1010 L·mol-1·s-1.
