2003/01/15 by Kang-Hun Ahn, Pritiraj Mohanty · 1 citation
Materials Science · Physics and Astronomy · #Carbon Nanotubes in Composites #Force Microscopy Techniques and Applications #Mechanical and Optical Resonators #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevlett.90.085504
To apear in Phys. Rev. Lett
arxiv created 2003/01/15 · openalex publication_date 2003/02/26 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Dissipation of micro- and nanoscale mechanical structures is dominated by quantum-mechanical tunneling of two-level defects intrinsically present in the system. We find that at high frequencies-usually, for smaller, micron-scale structures-a novel mechanism of phonon pumping of two-level defects gives rise to weakly temperature-dependent internal friction, Q-1, concomitant to the effects observed in recent experiments. Because of their size, comparable to or shorter than the emitted phonon wavelength, these structures suffer from superradiance-enhanced dissipation by the collective relaxation of a large number of two-level defects contained within the wavelength.