A technique to measure the decoherence time of optical phonons in a solid is presented. Phonons are excited with a pair of time delayed 80 fs, near infrared pulses via spontaneous, transient Raman scattering. The fringe visibility of the resulting Stokes pulse pair, as a function of time delay, is used to measure the phonon dephasing time. The method avoids the need to use either narrow band or few femtosecond pulses and is useful for low phonon excitations. The dephasing time of phonons created in bulk diamond is measured to be tau = 6.8ps (1.56cm-1).
@article{arxiv.0805.1668,
title = {Decoherence measurement of single phonons using spectral interference},
author = {F. C. Waldermann and B. J. Sussman and J. Nunn and V. O. Lorenz and K. C. Lee and K. Surmacz and K. H. Lee and D. Jaksch and I. A. Walmsley and P. Spizziri and P. Olivero and S. Prawer},
journal= {arXiv preprint arXiv:0805.1668},
year = {2008}
}
Comments
13 pages, 5 figures. Rewritten version with added theory section