Harmonic behavior of silicon nanowire by molecular dynamics

Silicon nanowires (SiNW) have attracted increasing interests as potential core parts for nanoscale devices due to their distinguished mechanical and electrical properties. Using molecular dynamics (MD) method, we investigated the vibration behaviors of SiNW on the atomic scale, including the fundamental mode frequency and quality factor. The quality factor as low as 120 is attributed to the energy loss process coming from atomic friction and nonlinearity. We also found that the energy of lattice vibration (phonon energy) is much larger than the macroscale beam vibration energy. And both the energies are less than the surface relaxation energy of the beam. The comparison between MD and FEM has been made to discuss the validity of continuum approximation for the study of SiNW.