| Автор | P D S Sacramento |
| Автор | V R Vieira |
| Дата выпуска | 1988-06-10 |
| dc.description | The Helmholtz free-energy functional of the correlation functions for quantum spin-1/2 systems is studied, using field theoretical methods. It is shown that it does not coincide with the first Legendre transform of the effective action obtained by a Hubbard-Stratonovich transformation. It is instead related to the second Legendre transform of the original action, thereby confirming that approximations for this functional are conservative in the Baym and Kadanoff sense. The critical behaviour of the Ising model in a transverse field is discussed as an example. |
| Формат | application.pdf |
| Издатель | Institute of Physics Publishing |
| Название | The Helmholtz free-energy functional for quantum spin-<sup>1</sup>/<sub>2</sub> systems |
| Тип | paper |
| DOI | 10.1088/0022-3719/21/16/022 |
| Print ISSN | 0022-3719 |
| Журнал | Journal of Physics C: Solid State Physics |
| Том | 21 |
| Первая страница | 3099 |
| Последняя страница | 3131 |
| Аффилиация | P D S Sacramento; Inst. Superior Tecnico de Lisboa, Inst. Nacional de Investigacia Cientifica, Lisboa, Portugal |
| Аффилиация | V R Vieira; Inst. Superior Tecnico de Lisboa, Inst. Nacional de Investigacia Cientifica, Lisboa, Portugal |
| Выпуск | 16 |
