Higher-order Coulomb correlation in the nonlinear optical response

Abstract

The influence of exciton-amplitude fluctuations and six-particle correlation is Studied beyond the third-order nonlinear optical response using the microscopic theory based on the correlation function approach. The results are exact to fifth order in the external laser field and can be used to interpret recent six-wave-mixing experiments. In the absence of phonons or a bath system, the replacement of two-point density matrices by exciton-amplitude fluctuations is no longer possible in the fifth-order nonlinear optical response. A correlation function is derived, which transparently includes genuine six-particle effects and possibly triexciton resonances.