title: Switchable Coupling of Vibrations to Two-Electron Carbon-Nanotube Quantum Dot States.
abstract: We report transport measurements on a quantum dot in a partly suspended carbon nanotube. Electrostatic tuning allows us to modify and even switch "on" and "off" the coupling to the quantized stretching vibration across several charge states. The magnetic-field dependence indicates that only the two-electron spin-triplet excited state couples to the mechanical motion, indicating mechanical coupling to both the valley degree of freedom and the exchange interaction, in contrast to standard models.
authors.affiliation: †2nd Institute of Physics, RWTH Aachen University, 52056 Aachen, Germany.|⊥ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels, Barcelona, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Weber
authors.affiliation: #Instituto de Física Enrique Gaviola (IFEG-CONICET) and FaMAF, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba, Argentina.
authors.forename: H L
authors.initials: HL
authors.lastname: Calvo
authors.forename: J
authors.initials: J
authors.lastname: Bohle
authors.affiliation: ∥Peter Grünberg Institute, Forschungszentrum Jülich, 52425 Jülich, Germany.|∇Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, Stuttgart, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Goß
authors.affiliation: ∥Peter Grünberg Institute, Forschungszentrum Jülich, 52425 Jülich, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Meyer
authors.affiliation: ∥Peter Grünberg Institute, Forschungszentrum Jülich, 52425 Jülich, Germany.
authors.forename: M R
authors.initials: MR
authors.lastname: Wegewijs
authors.affiliation: †2nd Institute of Physics, RWTH Aachen University, 52056 Aachen, Germany.|∥Peter Grünberg Institute, Forschungszentrum Jülich, 52425 Jülich, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Stampfer
keywords: Carbon nanotube; electron transport; electron-phonon coupling in low-dimensional structures; nanoelectromechanical systems (NEMS); quantum dot; spin states