Switchable Coupling of Vibrations to Two-Electron Carbon-Nanotube Quantum Dot States.
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.
['Weber|P|P|', 'Calvo|H L|HL|', 'Bohle|J|J|', 'Goß|K|K|', 'Meyer|C|C|', 'Wegewijs|M R|MR|', 'Stampfer|C|C|']
quantum dot Carbon nanotube electron transport electron-phonon coupling in low-dimensional structures nanoelectromechanical systems (NEMS) spin states