  We demonstrate that a supercurrent can pump energy from a battery that
provides a voltage bias into nanomechanical vibrations. Using a device
containing a nanowire Josephson weak link as an example we show that a
nonlinear coupling between the supercurrent and a static external magnetic
field leads to a Lorentz force that excites bending vibrations of the wire at
resonance conditions. We also demonstrate the possibility to achieve more than
one regime of stationary nonlinear vibrations and how to detect them via the
associated dc Josephson currents and we discuss possible applications of such a
multistable nanoelectromechanical dynamics.
