Application of the Dyson-type boson mapping for low-lying electron excited states in molecules

作者：Ohkido Sadao^*; Takahashi Makoto

来源：Progress of Theoretical and Experimental Physics, 2015, 2015(6): 063I01.

DOI：10.1093/ptep/ptv068

In many-electron systems, particularly when it is the case that the system consists of quasi-particles having almost no interaction with each other, the approaches to considering a quasi-particle to be a basic particle are important. We propose a bosonization method of the system in which a quasi-particle consists of electron-hole pairs. Low-lying electron excited states are approximately considered as the collective motion states of the quasi-particles that correspond to the quantized normal mode oscillations, and each of these quasi-particles consists of the electron-hole pairs. We consider the fundamental model Hamiltonian, and transform this into the quasi-particle representation Hamiltonian. Then, we transform these quasi-particles into bosons by using the Dyson-type boson mapping method. The obtained Dyson-type boson Hamiltonian enables a straightforward interpretation of the low-lying electron excited states and facilitates their calculation. To confirm the usefulness of this method, we apply this to the pi-electrons system of the ethylene molecule.

• 出版日期2015-6