Dear Tarun,

The DMRG code is computing the entanglement entropy during the optimization process. You can access these data with the function: iter = pyalps.loadMeasurements(pyalps.getResultFiles(prefix='parm_spin_one_half'), what=[ 'Iteration Entropy'])

I'm attaching an extension of the DMRG tutorial 01, which is also plotting entanglement entropy.

If you are just interested at the final results, you could just consider the last iteration.

Regards, Michele

-- ETH Zurich Michele Dolfi Institute for Theoretical Physics HIT G 32.4 Wolfgang-Pauli-Str. 27 8093 Zurich SWITZERLAND

dolfim@phys.ethz.ch www.itp.phys.ethz.ch

+41 44 633 78 56 phone +41 44 633 11 15 fax

Il giorno 15-giu-2012, alle ore 03:27, grover@berkeley.edu ha scritto:

Hi All!

I am very new to ALPS and trying to use it for DMRG of simple one-dimensional models. I would be thankful if someone can point out to me the python command in ALPS to access entanglement entropy (or better, the entanglement spectrum) that is generated at the end of DMRG convergence.

Thank you, Sincerely, Tarun

ps: I am assuming that the entanglement entropy in ALPS DMRG corresponds to the partition that divides the system into two-halves.