Squeezed polarons in one dimension

Fu‐Cho Pu, Bao‐Heng Zhao

O. S. Barišić, S. Barišić

Q.-H Chen, Yuhang Ren, Z.K. Jiao

Xiyu Su, Hang Zheng

An electron related squeezed phonon transformation is employed to investigate the ground state properties of the strongly coupled electron–phonon system in one dimension. It has been shown that the binding energy of the polaron and the interaction between the polarons are renormalized together with the energy reducement of the electron subsystem resulted from the squeeze state of the phonon subsystem. Some relevance with the earlier variational treatments has been discussed as well.

Chi‐Fai Lo, Roger Sollie

In this paper we have applied the correlated squeezed-state approach to investigate the ground-state properties of the one-dimensional Hubbard model with a local Holstein-type electron-phonon interaction. We have introduced a variational ground state in which the phonon subsystem is in a correlated squeezed state. The correlated squeezed state has built in the correlation between different phonon modes induced by the linear coupling with the electrons. With optimal values of the variational parameters the correlated squeezed state will by construction yield an energy lower than those obtained in earlier treatments. This means that our variational ansatz is more stable as the ground state of the system. Furthermore, our variational study shows that in the correlated squeezed state the polaronic reduction effect of phonons is much more alleviated, and thus the mass enhancement inherent to the polaron effect is considerably weakened. This weakening of the reduction effect should, in turn, affect other physical properties of the system.

V. I. Mel'Nikov, Григорий Ефимович Воловик