Ponderomotive and Magnetization Effects of Driving Voltage in a Metal Quantum Point Contact

We predict that the mesoscopic tensile force fluctuations in metal quantum point contacts (nanowires) arise as a result of finite electric voltage on the contact. They are due to reconfiguration of the electronic subsystem and are correlated with the nonlinearities of the current-voltage characteristics of the contact. The observation of the effect would directly confirm the recently suggested "free-electron" mechanism of mesoscopic force fluctuations observed in nanowires under deformation. The related magnetic susceptibility fluctuations and role of topology of the wire cross section are discussed as well