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How to assign different hopping parameter 't' to different sites

Posted: 06 Aug 2019, 19:49
by abhiroop
How do I assign different values hopping parameter 't' for different sites for fermionic hubbard model.
For a 12 site chain, I tried to multiply
model.lat.unit_cell = model.lat.unit_cell*12
and assign different values of t(i) (i = 1, 12) to each of the element of unit cell. But that is not matching with exact diagonalization results.

Re: How to assign different hopping parameter 't' to different sites

Posted: 07 Aug 2019, 09:33
by Johannes
You don't need to modify the unit_cell, if the kind of sites (Fermions with or without spin, Bosons, spins,...) doesn't change.
Instead, you can give a hopping parameter t which is not just a single number, but an array, specifying at which site you want hopping with which strength.

Take a look at the strength parameter and examples of add_coupling.

We've discussed the correct strength in viewtopic.php?f=7&t=6