Europhys. Lett, 44 (5), pp. 613-619 (1998)
Low-temperature dynamics of incommensurate biphenyl
as probed by
spectral hole burning
A. Suisalu 1, V. Zazubovich 1,2, J. Kikas 2, J. Friebel 3 and J. Friedrich 3
1 Institute of Physics, Riia 142 - EE2400 Tartu, Estonia
2 University of Tartu, Institute of Materials Science, Tähe 4 - EE2400 Tartu, Estonia
3 Technische Universität München, Lehrstuhl für Physik Weihenstephan
D-85350 Freising, Germany
(received 18 May 1998; accepted in final form 14 October 1998)
PACS. 61.44Fw - Incommensurate crystals.
PACS. 78.40 - Absorption and reflection spectra: visible and ultraviolet.
PACS. 33.70Jg - Line and band widths, shapes, and shifts.
We have measured the temperature dependence of the homogeneous width of spectral holes in the incommensurate phase III of chlorin-doped biphenyl from 60 mK to 10 K. Below 2 K a power law (, for different spectral peaks) prevails. Above 2 K a strong coupling to low-energy (5 and ) vibrational modes dominates. No indication of a low-temperature lock-in transition was found.