تقرير
Kadanoff-Baym equations and approximate double occupancy in a Hubbard dimer
| العنوان: | Kadanoff-Baym equations and approximate double occupancy in a Hubbard dimer |
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| المؤلفون: | von Friesen, M. Puig, Verdozzi, C., Almbladh, C. -O. |
| سنة النشر: | 2010 |
| المجموعة: | Condensed Matter |
| مصطلحات موضوعية: | Condensed Matter - Strongly Correlated Electrons |
| الوصف: | We use the Kadanoff-Baym equations within the framework of many-body perturbation theory to study the double occupancies in a Hubbard dimer. The double occupancies are obtained from the equations of motion of the single-particle Green's function. Our calculations show that the approximate double occupancies can become negative. This is a shortcoming of approximate, and yet conserving, many-body self-energies. Among the tested perturbation schemes, the T-matrix approximation is the only one providing double occupancies which are always positive. Comment: 2 pages, 1 figure |
| نوع الوثيقة: | Working Paper |
| URL الوصول: | http://arxiv.org/abs/1009.2917 |
| رقم الأكسشن: | edsarx.1009.2917 |
| قاعدة البيانات: | arXiv |
| الوصف غير متاح. |