Physics Practical Magic

Scientists figured out how to use the 'spin' of a single electron to physically crank a microscopic carbon engine.

March 16, 2026

Original Paper

Torsional oscillation of carbon nanotubes driven by electron spins

Koji Yamada, Wataru Izumida, Mamoru Matsuo, Takeo Kato

arXiv · 2603.12723

The Takeaway

By passing electricity through a suspended carbon nanotube, researchers can transfer quantum angular momentum directly from individual electrons into mechanical rotation. This allows for the creation of tiny motors driven entirely by the internal magnetic orientation of the flowing current.

From the abstract

We theoretically investigate the current-induced excitation of torsional vibrations in a suspended carbon nanotube (CNT) quantum dot. By considering a CNT clamped between half-metallic ferromagnetic electrodes with an antiparallel magnetization configuration, we demonstrate that the spin-rotation coupling enables the transfer of angular momentum from electron spins to the mechanical torsional mode under a constant source-drain voltage. Using a master-equation approach to analyze the coupled dyna