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Updated: Aug 9, 2026

Magnetic Tweezers for the Measurement of Twist and Torque
Published on: May 19, 2014
Current-induced rotation of helical molecular wires
1Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607, USA. pkral@uic.edu
Abstract:
We show that electric current running through a nanojunction with a biased helical molecule can induce unidirectional rotation of the molecular component. In an electric field, conduction electrons injected into the molecule are accelerated along the helical path going through its body, thereby gaining directed angular momentum. Conservation laws require that an angular momentum of the same size but opposite sense is imparted to the rigid-body rotation of the helix. We describe the angular momentum exchange processes that underlie the operation of the nanorotor, discuss factors limiting its efficiency, and propose potential applications.
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