title: Controlled Complete Suppression of Single-Atom Inelastic Spin and Orbital Cotunneling.
abstract: The inelastic portion of the tunnel current through an individual magnetic atom grants unique access to read out and change the atom's spin state, but it also provides a path for spontaneous relaxation and decoherence. Controlled closure of the inelastic channel would allow for the latter to be switched off at will, paving the way to coherent spin manipulation in single atoms. Here, we demonstrate complete closure of the inelastic channels for both spin and orbital transitions due to a controlled geometric modification of the atom's environment, using scanning tunneling microscopy (STM). The observed suppression of the excitation signal, which occurs for Co atoms assembled into chains on a Cu2N substrate, indicates a structural transition affecting the dz(2) orbital, effectively cutting off the STM tip from the spin-flip cotunneling path.
authors.affiliation: Department of Quantum Nanoscience, Kavli Institute of Nanoscience, Delft University of Technology , Lorentzweg 1, 2628 CJ Delft, The Netherlands.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Bryant
authors.affiliation: Department of Quantum Nanoscience, Kavli Institute of Nanoscience, Delft University of Technology , Lorentzweg 1, 2628 CJ Delft, The Netherlands.
authors.forename: Ranko
authors.initials: R
authors.lastname: Toskovic
authors.affiliation: International Iberian Nanotechnology Laboratory (INL) , Avenida Mestre José Veiga, 4715-330 Braga, Portugal.|Instituto de Modelado e Innovación Tecnológica (CONICET-UNNE) , Avenida Libertad 5400, W3404AAS Corrientes, Argentina.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Ferrón
authors.affiliation: International Iberian Nanotechnology Laboratory (INL) , Avenida Mestre José Veiga, 4715-330 Braga, Portugal.
authors.forename: José L
authors.initials: JL
authors.lastname: Lado
authors.affiliation: Department of Quantum Nanoscience, Kavli Institute of Nanoscience, Delft University of Technology , Lorentzweg 1, 2628 CJ Delft, The Netherlands.
authors.forename: Anna
authors.initials: A
authors.lastname: Spinelli
authors.affiliation: International Iberian Nanotechnology Laboratory (INL) , Avenida Mestre José Veiga, 4715-330 Braga, Portugal.|Departamento de Fı́sica Aplicada, Universidad de Alicante , San Vicente del Raspeig, 03690, Spain.
authors.forename: Joaquín
authors.initials: J
authors.lastname: Fernández-Rossier
authors.affiliation: Department of Quantum Nanoscience, Kavli Institute of Nanoscience, Delft University of Technology , Lorentzweg 1, 2628 CJ Delft, The Netherlands.
authors.forename: Alexander F
authors.initials: AF
authors.lastname: Otte
keywords: Magnetocrystalline anisotropy; scanning tunneling microscopy; spin excitation; strain