The influence of next-nearest-neighbor electron hopping t8 on the polaron and bipolaron formation in a square Hubbard-Holstein model is investigated within a variational approach. The results for electron-phonon and electron-electron correlation functions show that a negative value of t8 induces a strong anisotropy in the lattice distortions favoring the formation of nearest-neighbor intersite bipolaron. The role of t8, electronphonon and electron-electron interactions is briefly discussed in view of the formation of charged striped domains.
Polaron and bipolaron formation in the Hubbard-Holstein model: Role of next-nearest-neighbor electron hopping / De Filippis, G., Cataudella, V., Iadonisi, G., Marigliano Ramaglia, V., Perroni, C.A., Ventriglia, F.. - In: PHYSICAL REVIEW. B, CONDENSED MATTER. - ISSN 0163-1829. - STAMPA. - 64:(2001), pp. 155105-1-155105-7. [10.1103/PhysRevB.64.155105]
Polaron and bipolaron formation in the Hubbard-Holstein model: Role of next-nearest-neighbor electron hopping
G. De Filippis;CATAUDELLA, VITTORIO;PERRONI, CARMINE ANTONIO;VENTRIGLIA, FRANCO
2001
Abstract
The influence of next-nearest-neighbor electron hopping t8 on the polaron and bipolaron formation in a square Hubbard-Holstein model is investigated within a variational approach. The results for electron-phonon and electron-electron correlation functions show that a negative value of t8 induces a strong anisotropy in the lattice distortions favoring the formation of nearest-neighbor intersite bipolaron. The role of t8, electronphonon and electron-electron interactions is briefly discussed in view of the formation of charged striped domains.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
