Two-level systems observed in the mechanical properties of single-crystal silicon at low temperatures. Academic Article uri icon


  • Using the high-Q mechanical-oscillator technique we have measured the sound velocity and mechanical dissipation of high-purity single-crystal silicon as functions of temperature (0.0054.2 K), frequency (0.66.0 kHz), and strain amplitude (10-510-8). In the mechanical properties we find a surprisingly strong temperature dependence with the same qualitative behavior for silicon as for vitreous silica. This implies a density of two-level systems only 2 orders of magnitude lower for silicon than amorphous silica. In silicon we find evidence for a new dissipation mechanism at low temperatures and report the first observation of a saturation with strain of the resonant contribution to the sound velocity. 1987 The American Physical Society.

published proceedings

  • Phys Rev Lett

altmetric score

  • 6

author list (cited authors)

  • Kleiman, R. N., Agnolet, G., & Bishop, D. J.

citation count

  • 69

complete list of authors

  • Kleiman, RN||Agnolet, G||Bishop, DJ

publication date

  • November 1987