1306.5073 (P. Nalbach et al.)

Strong coupling theory for crystalline tunnelling defects coupled to
phonons    [PDF]

P. Nalbach, M. Schechter

We determine the linear acoustic and dielectric response of crystalline tunnelling defects assuming strong coupling to phonons. Whereas at weak defect phonon coupling the cubic geometry of the typical host crystals dictates the response, for strong defect phonon coupling the symmetry is reduced effectively to inversion symmetry. Strong defect phonon coupling suppresses otherwise dominant tunnelling path and only tunnelling along inversion symmetric paths prevail. This causes qualitatively different acoustic response for strong, compared to weak, defect phonon coupling. Thus, it allows a direct determination of the elastic coupling strength from experimental data.

View original: http://arxiv.org/abs/1306.5073