Photon echo study of the electron-phonon coupling strength in molecules and molecular aggregates

Abstract

A method for direct measurement of the system-bath coupling strength in molecules and molecular aggregates, based on the three pulse photon echo technique with non-trivial time ordering of interacting laser pulses, is proposed and realized. A surprisingly low magnitude of the Huang-Rhys factor (∼ 1) was measured for the natural molecular aggregates (chlorosomes from the Cf. aurantiacus bacteria) at room temperature.