تقرير
Electronic and magnetic properties of the topological semimetal SmMg$_2$Bi$_2$
| العنوان: | Electronic and magnetic properties of the topological semimetal SmMg$_2$Bi$_2$ |
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| المؤلفون: | Kundu, Asish K., Pakhira, Santanu, Roy, Tufan, Yilmaz, T., Tsujikawa, Masahito, Shirai, Masafumi, Vescovo, E., Johnston, D. C., Pasupathy, Abhay N., Valla, Tonica |
| المصدر: | Phys. Rev. B 106, 245131 (2022) |
| سنة النشر: | 2022 |
| المجموعة: | Condensed Matter |
| مصطلحات موضوعية: | Condensed Matter - Strongly Correlated Electrons |
| الوصف: | Dirac semimetals show nontrivial physical properties and can host exotic quantum states like Weyl semimetals and topological insulators under suitable external conditions. Here, by combining angle-resolved photoemission spectroscopy measurements (ARPES) and first-principle calculations, we demonstrate that Zintl-phase compound SmMg$_2$Bi$_2$ belongs to the close proximity to a topological Dirac semimetallic state. ARPES results show a Dirac-like band crossing at the zone-center near the Fermi level ($E_\mathrm {F}$) which is further confirmed by first-principle calculations. Theoretical studies also reveal that SmMg$_2$Bi$_2$ belongs to a $Z_2$ topological class and hosts spin-polarized states around the $E_\mathrm {F}$. Zintl's theory predicts that the valence state of Sm in this material should be Sm$^{2+}$, however we detect many Sm-4$f$ multiplet states (flat-bands) whose energy positions suggest the presence of both Sm$^{2+}$ and Sm$^{3+}$. It is also evident that these flat-bands and other dispersive states are strongly hybridized when they cross each other. Due to the presence of Sm$^{3+}$ ions, the temperature dependence of magnetic susceptibility $\chi(T)$ shows Curie-Weiss-like contribution in the low temperature region, in addition to the Van Vleck-like behaviour expected for the Sm$^{2+}$ ions. The present study will help in better understanding of the electronic structure, magnetism and transport properties of related materials. Comment: 11 pages, 7 figures |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1103/PhysRevB.106.245131 |
| URL الوصول: | http://arxiv.org/abs/2209.12109 |
| رقم الأكسشن: | edsarx.2209.12109 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1103/PhysRevB.106.245131 |
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