Year: 2026
Type: preprint
Abstract: We theoretically investigate electronic driving of a torsional mode in a suspended carbon nanotube quantum dot. The valley states in a nanotube carry opposite orbital magnetic moments along the tube axis, and intervalley mixing forms valley-mixed eigenstates whose splitting can be controlled by an axial magnetic field. We formulate an orbital-rotation coupling between the torsional angular velocity and the valley orbital angular momentum. Using a master equation for sequential tunneling through normal-metal electrodes, we calculate the steady-state current and the phonon distribution of the torsional mode. When the valley-state splitting matches the torsional phonon energy, orbital transitions can drive the mode out of equilibrium. The contacts control both phonon pumping and its electrical readout, allowing substantial excitation with a positive, vanishing, or negative current response. The mechanism requires no intrinsic spin or valley polarization of the electrodes, but uses state-dependent tunneling at the contacts.
Source: arXiv (Cornell University)
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Award: G920057190
OpenAlex ID: W7223154067