Mechanical properties of suspended structures at radio frequencies

We report on our work on nanomechanical resonators. The resonators are mach ined out of commercial silicon-on-insulator (SOI) material with a covering metal layer having eigenfrequencies in the radio frequency (RF) regime. At higher oscillating amplitudes they are driven into nonlinear response. The properties of the nonlinear resonators can be used for charge detection. Fu rthermore, we report on first experiments on using these resonators for exc iting phonon and roton modes in He-4. (C) 2000 Elsevier Science B.V. All ri ghts reserved.