Dear Matthias,
Thank you for your reply. I have one more question about DMRG.
I try to calculate a gap of xxz spin model (Jz != Jxy) for different values of Jz and Jxy. I think that it will be more safe to assume that I do not know in what Sz sector search for a ground and excited states.
Is it in this case better option to run simulation over all possible Sz by hand or to comment a line #'Sz_total' : Sz.
which should force alps to work in the grand canonical as it was told in the first tutorial on the webpage?
I tried this second approach for the ising model (Jxy = 0, Jz = 1) but what I get was just a duplicated ground state without a correct excited state.
Bests, Rafał
2013/11/18 Matthias Troyer troyer@phys.ethz.ch
Yes, you can drop it if N does not exist
On Nov 18, 2013, at 21:33, Rafał arymanus@gmail.com wrote:
Dear all ALPS users,
I have following questions to the DMRG tutorials. Why there is N in a
line:
'CONSERVED_QUANTUMNUMBERS' : 'N,Sz',
I understand that Sz stands for conserved quantum number but spin model
on the open chain lattice does not have quantum number called N.
Is this N added to 'CONSERVED_QUANTUMNUMBERS' just in case someone may
use some bosonic model?
Bests, Rafał