تقرير
Can we always get the entanglement entropy from the Kadanoff-Baym equations? The case of the T-matrix approximation
| العنوان: | Can we always get the entanglement entropy from the Kadanoff-Baym equations? The case of the T-matrix approximation |
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| المؤلفون: | von Friesen, M. Puig, Verdozzi, C., Almbladh, C. -O. |
| سنة النشر: | 2011 |
| المجموعة: | Condensed Matter |
| مصطلحات موضوعية: | Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Quantum Gases, Condensed Matter - Strongly Correlated Electrons |
| الوصف: | We study the time-dependent transmission of entanglement entropy through an out-of-equilibrium model interacting device in a quantum transport set-up. The dynamics is performed via the Kadanoff-Baym equations within many-body perturbation theory. The double occupancy $< \hat{n}_{R \uparrow} \hat{n}_{R \downarrow} >$, needed to determine the entanglement entropy, is obtained from the equations of motion of the single-particle Green's function. A remarkable result of our calculations is that $< \hat{n}_{R \uparrow} \hat{n}_{R \downarrow} >$ can become negative, thus not permitting to evaluate the entanglement entropy. This is a shortcoming of approximate, and yet conserving, many-body self-energies. Among the tested perturbation schemes, the $T$-matrix approximation stands out for two reasons: it compares well to exact results in the low density regime and it always provides a non-negative $< \hat{n}_{R \uparrow} \hat{n}_{R \downarrow} >$. For the second part of this statement, we give an analytical proof. Finally, the transmission of entanglement across the device is diminished by interactions but can be amplified by a current flowing through the system. Comment: 6 pages, 6 figures |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1209/0295-5075/95/27005 |
| URL الوصول: | http://arxiv.org/abs/1103.4054 |
| رقم الأكسشن: | edsarx.1103.4054 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1209/0295-5075/95/27005 |
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