Dear Javier Vijande,
I would like to know if it is possible to implement within ALPS hamiltonians with imaginary terms like:
H=-i*Sum_{<i,j>} ( K_{ij}*[b(i)*bdag(j)-bdag(i)*b(j)])
(b and bdag are the usual creation/annihilation operators, K_{ij} is a parameter and i is the complex unit, i^2=-1)
To express unit imaginary in model XML files, please use 'I' instead of 'i'. The ALPS expression and model libraries themselves fully support the complex numbers in the Hamiltonian. I believe full and sparse diag applications also support (complex) Hermitian matrices.
Best, Synge