On Thu, Dec 15, 2022 at 5:18 AM 後藤達也 <
t.g...@j-ij.com> wrote:
> Simon, thank you for your sample code !!
> Your code work fine in my case as well.
Pleasure!
> What effect is max_depth expected to have on the results?
- Nk controls the number of expansion terms used to approximate the
bath correlation function (and hence spectral density).
- The terminator adds a Markovian approximation of the infinite set of
terms discarded from the expansion of the bath correlation function
(terms above Nk).
- max_depth specifies the number of levels to retain in the hierarchy
To tell if a solution has converged, one does typically have to try
higher Nk and max_depths and see if the resulting dynamics change, but
there are also some heuristics:
- If interaction with the environment is weak, one needs only small Nk
and max_depth, and the terminator can capture most of the dynamics.
- If interaction with the environment is strong, one needs a
sufficiently large Nk to accurately model the spectral density of the
environment and then a big enough max_depth to cope with resulting
interactions within the bath / environment itself.
Since with large enough Nk and max_depth the HEOM can potentially
model any open quantum system, fully characterising the dynamics is
challenging, and I'm not aware of any work which does so.
Regards,
Simon