Fidelity coming low

[anir...@gmail.com]

I was just checking the fidelity of a final GHZ state, for which the fidelity was coming too low than expected. My real concern is before I perform a gate to build the GHZ state, I prepare the bell state, for which the fidelity was fine. I sit something related to some numerical errors?. I recently checked one of your blogs that often when you are running mesolve for a long time interval, then the density matrix becomes non hermitian. Is it a cause for the error?