Origin of slow magnetic relaxation in Kramers ions with non-uniaxial anisotropy

Gómez-Coca, S. ; Urtizberea, A. ; Cremades, E. ; Alonso, P. J. ; Camón, A. (Universidad de Zaragoza) ; Ruiz, E. ; Luis, F. (Universidad de Zaragoza)

Resumen: Transition metal ions with long-lived spin states represent minimum size magnetic bits. Magnetic memory has often been associated with the combination of high spin and strong uniaxial magnetic anisotropy. Yet, slow magnetic relaxation has also been observed in some Kramers ions with dominant easy-plane magnetic anisotropy, albeit only under an external magnetic field. Here we study the spin dynamics of cobalt(II) ions in a model molecular complex. We show, by means of quantitative first-principles calculations, that the slow relaxation in this and other similar systems is a general consequence of time-reversal symmetry that hinders direct spin–phonon processes regardless of the sign of the magnetic anisotropy. Its magnetic field dependence is a subtle manifestation of electronuclear spin entanglement, which opens relaxation channels that would otherwise be forbidden but, at the same time, masks the relaxation phenomenon at zero field. These results provide a promising strategy to synthesize atom-size magnetic memories.

Idioma: Inglés

DOI: 10.1038/ncomms5300

Año: 2014

Publicado en: Nature communications 5 (2014), 4300 [8 pp.]
ISSN: 2041-1723

Factor impacto JCR: 11.47 (2014)

Categ. JCR: MULTIDISCIPLINARY SCIENCES rank: 3 / 57 = 0.053 (2014) - Q1 - T1

Financiación: info:eu-repo/grantAgreement/ES/DGA/E98-MOLCHIP
Financiación: info:eu-repo/grantAgreement/ES/MINECO/CTQ2011-23862-C02-01
Financiación: info:eu-repo/grantAgreement/ES/MINECO/MAT2011-23861
Financiación: info:eu-repo/grantAgreement/ES/MINECO/MAT2012-38318-C03

Tipo y forma: Artículo (Versión definitiva)

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