Decoherence measurement of single phonons using spectral interference

TL;DR

This paper introduces a spectral interference technique to measure the decoherence time of optical phonons in solids, using transient Raman scattering and fringe visibility analysis, applicable to low phonon excitations.

Contribution

It presents a novel method for measuring phonon decoherence times that does not require narrow band or ultrashort pulses, improving accessibility and applicability.

Findings

Measured phonon dephasing time in diamond: 6.8 ps

Method effectively captures phonon decoherence without complex pulse shaping

Applicable to low phonon excitation levels

Abstract

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).