Calculations of nonlinear spectra of liquid Xe. II. Fifth-order Raman response

The polarization dependence and temporal profile of the fifth-order Raman response function and corresponding correlation function in liquid Xe are studied both analytically and numerically. Based on the symmetry of an isotropic sample, the fifth-order Raman response function has twelve distinct tensor elements, ten of which are independent, and the corresponding correlation function has twelve distinct tensor elements, seven of which are independent. The coefficients for decomposition into independent components are calculated explicitly based on the tensor property of an isotropic sample and are used to identify different coupling mechanisms in liquid Xe. The two-dimensional profile of the fifth-order Raman response function is evaluated by a simple hydrodynamic expression derived using the Gaussian factorization scheme. An alternative approach reduces the fifth-order Raman response function to time correlation functions that are easy to compute. (C) 2002 American Institute of Physics.