Diagrammatic evaluation of the density operator for nonlinear optical calculations

Vibrational polarization beats in femtosecond coherent anti-Stokes Raman spectroscopy: A signature of dissociative pump–dump–pump wave packet dynamics

“…In Sec. II B we present a diagrammatic representation of resonant four-wave mixing using double-sided Feynman diagrams [23][24][25][26]65 to illustrate the connection between the wave function and density matrix pathways that contribute to the signal. In Sec.…”

“…The spectroscopic pathways that produce the third order polarization in Eq. ͑11͒ may be depicted using double-sided Feynman diagrams, [23][24][25][26]65 as shown in Fig. 3.…”

Line shape and Doppler broadening in resonant CARS and related nonlinear processes through a diagrammatic approach

“…-The density operator at any specified order can be shown to result from a number of contributions ; each of these is associated with a specific time sequence of perturbations to the density operator, or to the ket vector 1 t/1 > and its complex conjugate t/11 1 (in the pure state case) ; the timeordering of the perturbations to 1 t/1 > with respect to those to t/11 is of crucial importance in the case of collisional relaxation. It has been demonstrated that each of these elementary time-ordered contributions can be visualized by means of a double-sided Feynmanlike diagram, which can be used to write down directly the associated density matrix contribution [12][13][14][15][16][17].…”

The factorization approximation for the Master Equation

“…We wish to mention some attempts [11], which were made, to apply perturbation expansion to the time evolution of the reduced density matrix, but only the lowest order terms were calculated. Keldysh [12] used the conventional Feynmann diagrams of field theory to develop a general theory of the time evolution of the density matrix.…”