Extracting joint state from QuTiP HEOM Solver for spin-boson model
Mohan Chaundry
Hey!
I’m working with the QuTiP HEOM solver (as described in this documentation) to simulate the dynamics of a spin-boson model, specifically using Eq.(1) from the paper on the QuTiP HEOM solver (link to paper). I’m using one of the spectral densities mentioned in the paper, such as the Drude-Lorentzian.
I noticed that the solver outputs reduced density matrices in the system Hilbert space only. Is there a way to obtain the state in the joint system-bath Hilbert space? From Eq.(3) in the paper, it seems like the HEOM is solving for a state that acts on the joint system, so in principle, it should be possible to extract this state. However, I’m not sure how to do this using the functions provided in the examples on the QuTiP documentation page.
Has anyone successfully extracted the joint system-bath state using the HEOM solver, or is there a specific method to achieve this? Any guidance would be greatly appreciated!
Simon Cross
If you set the `store_ados` option when creating or running the HEOM
solver, then the full ADOs will be available as `.ado_states` on the
result. This is documented in
https://qutip.readthedocs.io/en/latest/apidoc/heom.html#qutip.solver.heom.HEOMResult,
but the documentation is a unclear.
Hope this helps.
Regards,
Simon