Keep running into the problem of "stiff configuration"

Hello Team,
I am running and experimenting with bloqade python from the tutorials. But that requires me to change a few of the parameters resulting in the following interruption.

   "DOP853/DOPRI5: Problem is probably <mark>stiff</mark> (interrupted)."

Why this is happening? Is it saying that the differential equation it needs to solve is stiff or something else? I don’t really know how bloqade solves the Schrodinger equation of the system. And most importantly, what do I have to make sure to not run into this again?

Thank you so much for your help

When the atoms are too close, the Rydberg interaction can create a large term in the Hamiltonian, making integrating difficult.

In this case, you can try two things:

  1. Set interaction_picture=True option in the solver
  2. Work with the blockade subspace by setting blockade_radius=... to equal the minimum atom spacing.
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