Chemical disorder in topological insulators: A route to magnetism tolerant Topological surface States

Martínez Velarte, Maria del Carmen ; Kretz, Bernhard ; Moro-Lagares, María ; Aguirre, Myriam Haydee (Universidad de Zaragoza) ; Riedemann, Trevor M. ; Lograsso, Thomas A. ; Morellon, Luis (Universidad de Zaragoza) ; Ibarra, M Ricardo (Universidad de Zaragoza) ; Garcia-Lekue, Aran ; Serrate, David (Universidad de Zaragoza)

Resumen: We show that the chemical inhomogeneity in ternary 3D topological insulators preserves the topological spin texture of their surface states against a net surface magnetization. The spin texture is that of a Dirac cone with helical spin structure in the reciprocal space, which gives rise to spin-polarized and dissipation-less charge currents. Thanks to the non-trivial topology of the bulk electronic structure, this spin texture is robust against most types of surface defects. However, magnetic perturbations break the time-reversal symmetry, enabling magnetic scattering and loss of spin coherence of the charge carriers. This intrinsic incompatibility precludes the design of magnetoelectronic devices based on the coupling between magnetic materials and topological surface states. We demonstrate that the magnetization coming from individual Co atoms deposited on the surface can disrupt the spin coherence of the carriers in the archetypal topological insulator Bi2Te3, while in Bi2Se2Te the spin texture remains unperturbed. This is concluded from the observation of elastic backscattering events in quasiparticle interference patterns obtained by scanning tunneling spectroscopy. The mechanism responsible for the protection is investigated by energy resolved spectroscopy and ab-initio calculations, and it is ascribed to the distorted adsorption geometry of localized magnetic moments due to Se-Te disorder, which suppresses the Co hybridization with the surface states

Idioma: Inglés

DOI: 10.1021/acs.nanolett.7b00311

Año: 2017

Publicado en: Nano Letters 17, 7 (2017), 4047-4054
ISSN: 1530-6984

Factor impacto JCR: 12.08 (2017)

Categ. JCR: CHEMISTRY, PHYSICAL rank: 11 / 146 = 0.075 (2017) - Q1 - T1
Categ. JCR: MATERIALS SCIENCE, MULTIDISCIPLINARY rank: 19 / 285 = 0.067 (2017) - Q1 - T1
Categ. JCR: NANOSCIENCE & NANOTECHNOLOGY rank: 10 / 92 = 0.109 (2017) - Q1 - T1
Categ. JCR: PHYSICS, CONDENSED MATTER rank: 8 / 67 = 0.119 (2017) - Q1 - T1
Categ. JCR: CHEMISTRY, MULTIDISCIPLINARY rank: 15 / 171 = 0.088 (2017) - Q1 - T1
Categ. JCR: PHYSICS, APPLIED rank: 9 / 146 = 0.062 (2017) - Q1 - T1

Factor impacto SCIMAGO: 7.447 - Bioengineering (Q1) - Chemistry (miscellaneous) (Q1) - Nanoscience and Nanotechnology (Q1) - Materials Science (miscellaneous) (Q1) - Mechanical Engineering (Q1) - Condensed Matter Physics (Q1)

Financiación: info:eu-repo/grantAgreement/ES/DGA/E26
Financiación: info:eu-repo/grantAgreement/EC/FP7/304043/EU/High Performance Energy Conversion by the interplay between Thermoelectricity and Spin Seebeck Effect/THERMO-SPINTRONIC
Financiación: info:eu-repo/grantAgreement/ES/MINECO/MAT2013-46593-C6-2-P
Financiación: info:eu-repo/grantAgreement/ES/MINECO/MAT2013-46593-C6-3-P

Tipo y forma: Article (PostPrint)

Área (Departamento): Área Física Materia Condensada (Dpto. Física Materia Condensa.)