Effect of the ac field on a single-molecule magnet bridged between conducting leads

► Magnetic molecules (MM) have been proposed as ultimate units of magnetic memory. ► Several experiments were performed to measure electric current through a single molecule. ► We study mechanical vibrations of a MM bridged between two leads in the presence of ac and dc fields. ► Through quantum spin-rotation coupling such fields generate mechanical motion of the molecule. ► The twist of the molecule can be detected by measuring the tunneling current through the molecule.