UniSa - IRIS Institutional Research Information System
IRIS è la soluzione IT che facilita la raccolta e la gestione dei dati relativi alle attività e ai prodotti della ricerca. Fornisce a ricercatori, amministratori e valutatori gli strumenti per monitorare i risultati della ricerca, aumentarne la visibilità e allocare in modo efficace le risorse disponibili.
EnglishThe electronic states of the Hubbard model are investigated by use of the composite operator method. In addition to the Hubbard operators, two other operators related with two-site composite excitations are included in the basis. Within the present formulation, higher-order composite excitations are reduced to the chosen operatorial basis by means of a procedure preserving the particle-hole symmetry. The positive comparison with numerical simulations for the double occupancy indicates that such approximation improves over the two-pole approximation. © 2003 Elsevier B.V. All rights reserved.
| Titolo: | Effects of two-site composite excitations in the Hubbard model | |
| Autori: | ||
| Data di pubblicazione: | 2004 | |
| Rivista: | ||
| Abstract: | The electronic states of the Hubbard model are investigated by use of the composite operator method. In addition to the Hubbard operators, two other operators related with two-site composite excitations are included in the basis. Within the present formulation, higher-order composite excitations are reduced to the chosen operatorial basis by means of a procedure preserving the particle-hole symmetry. The positive comparison with numerical simulations for the double occupancy indicates that such approximation improves over the two-pole approximation. © 2003 Elsevier B.V. All rights reserved. | |
| Handle: | http://hdl.handle.net/11386/1064265 | |
| Appare nelle tipologie: | 1.1.2 Articolo su rivista con ISSN |
File in questo prodotto:
http://hdl.handle.net/11386/1064265
Copyright © 2021