  We suggest a new type of nano-electromechanical resonator, the functionality
of which is based on a magnetic field induced deflection of an appropriate
cantilever that oscillates between nitrogen vacancy (NV) spins in daimond.
Specifically, we consider a Si(100) cantilever coated with a thin magnetic Ni
film. Magnetoelastic stress and magnetic-field induced torque are utilized to
induce a controlled cantilever deflection. It is shown that, depending on the
value of the system parameters, the induced asymmetry of the cantilever
deflection substantially modifies the characteristics of the system. In
particular, the coupling strength between the NV spins and the degree of
entanglement can be controlled through magnetoelastic stress and magnetic-field
induced torque effects. Our theoretical proposal can be implemented
experimentally with the potential of increasing several times the coupling
strength between the NV spins as compared to the maximal coupling strength
reported before in P. Rabl, et al. Phys. Rev. B 79, 041302(R) (2009).
