1 research outputs found
Semiclassical Path Integral Calculation of Nonlinear Optical Spectroscopy
Computation of nonlinear
optical response functions allows for
an in-depth connection between theory and experiment. Experimentally
recorded spectra provide a high density of information, but to objectively
disentangle overlapping signals and to reach a detailed and reliable
understanding of the system dynamics, measurements must be integrated
with theoretical approaches. Here, we present a new, highly accurate
and efficient trajectory-based semiclassical path integral method
for computing higher order nonlinear optical response functions for
non-Markovian open quantum systems. The approach is, in principle,
applicable to general Hamiltonians and does not require any restrictions
on the form of the intrasystem or system–bath couplings. This
method is systematically improvable and is shown to be valid in parameter
regimes where perturbation theory-based methods qualitatively breakdown.
As a test of the methodology presented here, we study a system–bath
model for a coupled dimer for which we compare against numerically
exact results and standard approximate perturbation theory-based calculations.
Additionally, we study a monomer with discrete vibronic states that
serves as the starting point for future investigation of vibronic
signatures in nonlinear electronic spectroscopy