Hello ALPS community,
First, sorry for my English and for the trivial question that I'm going
to ask you.
I already made the tutorial on the S=(1/2, 1) antiferromagnetic
Heisenberg chain where
I found the correlation function and the gap in the thermodynamic limit
(for S = 1). Now,
I'm trying to do the same thing for the S=1/2 ferromagnetic Heisenberg
chain but I guess I made
a mistake when we have to specify the different parameters. Here is what
I wrote in my computer
code :
parms.append({
'LATTICE' : 'open chain lattice',
'MODEL' : 'spin',
'CONSERVED_QUANTUMNUMBERS' : 'N,Sz',
'Sz_total' : 0,
'J' : -1,
'SWEEPS' : 4,
'NUMBER_EIGENVALUES' : 1,
'L' : 32,
'MAXSTATES' : 20,
'MEASURE_CORRELATIONS[Diagonal spin correlations]' : 'Sz',
})
but the result is completely wrong. I only modify the sign of the
coupling constant compared to the antiferromagnetic case.
Thank you in advance for your help,
Best regards,
Julien