تقرير
Quantum geometric bound for saturated ferromagnetism
| العنوان: | Quantum geometric bound for saturated ferromagnetism |
|---|---|
| المؤلفون: | Kang, Junha, Oh, Taekoo, Lee, Junhyun, Yang, Bohm-Jung |
| سنة النشر: | 2024 |
| المجموعة: | Condensed Matter |
| مصطلحات موضوعية: | Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Mesoscale and Nanoscale Physics |
| الوصف: | Despite its abundance in nature, predicting the occurrence of ferromagnetism in the ground state is possible only under very limited conditions such as in a flat band system with repulsive interaction or in a band with a single hole under infinitely large Coulomb repulsion, etc. Here, we propose a general condition to achieve saturated ferromagnetism based on the quantum geometry of electronic wave functions in itinerant electron systems. By analyzing multi-band repulsive Hubbard models with an integer band filling, relevant to either ferromagnetic insulators or semimetals, we propose a rigorous quantum geometric upper bound on the spin stiffness. By employing this geometric bound, we establish that saturated ferromagnetism is prohibited in the absence of interband coupling, even when the local Hubbard repulsion is infinitely large. As a corollary, this shows that saturated ferromagnetism is forbidden in any half-filled Hubbard model. We also derive the condition that the upper bound of the spin stiffness can be completely characterized by the Abelian quantum metric. We believe that our findings reveal a profound connection between quantum geometry and ferromagnetism, which can be extended to various symmetry-broken ground states in itinerant electronic systems. Comment: 7+10 pages, 3+1 figures |
| نوع الوثيقة: | Working Paper |
| URL الوصول: | http://arxiv.org/abs/2402.07171 |
| رقم الأكسشن: | edsarx.2402.07171 |
| قاعدة البيانات: | arXiv |
| الوصف غير متاح. |