Scalar relaxation superoperator using Redfield theory.
Computes Redfield superoperator in situations when the system has a static background Hamiltonian and a perturbation with a scalar stochastic function in front of it. Scalar hyperfine relaxation is a common example. This function is called by Spinach relaxation theory module, but may also be invoked directly.
H0 - background Hamiltonian H1 - the stochastically modulated interaction operator multiplied by its root mean square modulation depth tau_c - the correlation time of the stochastic modulation
R - relaxation superoperator as a negative definite matrix
If H1(t) has a non-zero average value, it must be subtracted out and put into H0.
Version 2.1, authors: Ilya Kuprov