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