Thank you for your quick answer. It has certainly been helpful.
Dear Kwant developers,
I've found in other threads in the mailing list that the units of current is for example (unit of charge)/(hbar/unit of energy) (https://email@example.com/msg01100.html). Also, the local density of states has units of energy/volume (https://firstname.lastname@example.org/msg00169.html).
My question is, what is the units of the output of the density operator? Is it energy/volume as well? I ask this because intuitively I view it as the square of the wavefunction, but it gives me values larger than 1 for each site when there is only 1 mode involved (see attached picture) so it is not just the probability of findinge the electron at that site because this should be maximum 1. I have also noticed that the values I get in the colorbar depend on the value of my hopping (e.g. case of graphene), but overall I'm not so sure of the units.
Thank you again for your help.