title: Tunneling splitting of Jahn-Teller ions in oxides.
abstract: The magnitude of tunneling splitting, 3Gamma, that governs decoherence in quantum systems under symmetric potentials, is frequently unknown. Using first-principles calculations, we have obtained 3Gamma for a number of E[symbol:see text]e Jahn-Teller impurities in solids. Calculated values span 6 orders of magnitude on passing from KCl:Ag{2+} to MgO:Cu{2+}. Values associated with Cu2+- and Ag2+-doped MgO are 2 orders of magnitude larger than those previously assumed and consistent with the existence of a dynamic Jahn-Teller effect. The origin and enhancement with pressure of these high 3Gamma values is discussed in detail.
authors.affiliation: Departamento de Ciencias de la Tierra y Física de la Materia Condensada, Universidad de Cantabria, Avenida de los Castros s/n. 39005 Santander, Spain.
authors.forename: P
authors.initials: P
authors.lastname: García-Fernández
authors.forename: A
authors.initials: A
authors.lastname: Trueba
authors.forename: M T
authors.initials: MT
authors.lastname: Barriuso
authors.forename: J A
authors.initials: JA
authors.lastname: Aramburu
authors.forename: M
authors.initials: M
authors.lastname: Moreno