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Your search keyword '"Garate, Ion"' showing total 22 results
Start Over Author "Garate, Ion" Publication Year Range Last 10 years Journal physical review b
22 results on '"Garate, Ion"'

19. Experimental evidence and control of the bulk-mediated intersurface coupling in topological insulatorBi2Te2Senanoribbons

Author

Li, Zhaoguo, primary, Garate, Ion, additional, Pan, Jian, additional, Wan, Xiangang, additional, Chen, Taishi, additional, Ning, Wei, additional, Zhang, Xiaoou, additional, Song, Fengqi, additional, Meng, Yuze, additional, Hong, Xiaochen, additional, Wang, Xuefeng, additional, Pi, Li, additional, Wang, Xinran, additional, Wang, Baigeng, additional, Li, Shiyan, additional, Reed, Mark A., additional, Glazman, Leonid, additional, and Wang, Guanghou, additional

Published
2015
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21. Tight-binding theory of NMR shifts in topological insulators Bi2Se3 and Bi2Te3.

Author

Boutin, Samuel, Ramírez-Ruiz, Jorge, and Garate, Ion

Subjects
*TOPOLOGICAL insulators, *NUCLEAR magnetic resonance, *SPIN-orbit interactions, *FERMI level, *HYPERFINE interactions
Abstract

Motivated by recent nuclear magnetic resonance (NMR) experiments, we present a microscopic sp³ tight-binding model calculation of the NMR shifts in bulk Bi2Se3 and Bi2Te3. We compute the contact, dipolar, orbital and core polarization contributions to the carrier-density-dependent part of the NMR shifts in 209Bi, 125Te, and 77Se. The spin-orbit coupling and the layered crystal structure result in a contact Knight shift with strong uniaxial anisotropy. Likewise, because of spin-orbit coupling, dipolar interactions make a significant contribution to the isotropic part of the NMR shift. The contact interaction dominates the isotropic Knight shift in 209Bi NMR, even though the electronic states at the Fermi level have a rather weak s-orbital character. In contrast, the contribution from the contact hyperfine interaction to the NMR shift of 77Se and 125Te is weak compared to the dipolar and orbital shifts therein. In all cases, the orbital shift is at least comparable to the contact and dipolar shifts, while the shift due to core polarization is subdominant (except for Te nuclei located at the inversion centers). By artificially varying the strength of spin-orbit coupling, we evaluate the evolution of the NMR shift across a band inversion but find no clear signature of the topological transition. [ABSTRACT FROM AUTHOR]

Published
2016
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22. 77Se nuclear magnetic resonance of topological insulator Bi2Se3.

Author

Georgieva, Nataliya M., Rybicki, Damian, Guehne, Robin, Williams, Grant V. M., Chong, Shen V., Kazuo Kadowaki, Garate, Ion, and Haase, Jürgen

Subjects
*NUCLEAR magnetic resonance, *SELENIUM compounds, *TOPOLOGICAL insulators
Abstract

Topological insulators constitute a new class of materials with an energy gap in the bulk and peculiar metallic states on the surface. We report on new features resulting from the bulk electronic structure, based on a comprehensive nuclear magnetic resonance (NMR) study of 77Se on Bi2Se3 and Cu0.15Bi2Se3 single crystals. First, we find two resonance lines and show that they originate from the two inequivalent Se lattice sites. Second, we observe unusual field-independent linewidths and attribute them to an unexpectedly strong internuclear coupling mediated by bulk electrons. In order to support this interpretation, we present a model calculation of the indirect internuclear coupling and show that the Bloembergen-Rowland coupling is much stronger than the Ruderman-Kittel-Kasuya-Yosida coupling. Our results call for a revision of earlier NMR studies and add information concerning the bulk electronic properties. [ABSTRACT FROM AUTHOR]

Published
2016
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