Dear Fernando,

Your e-mail was held back since you are not subscribed to the mailing list. It might be easiest if you subscribe. Indeed the worm code (and actually no QMC) cannot deal with complex terms, but maybe a change of basis can help. We'll be able to tell you whether this is possible if you post the full Hamiltonian.

Best regards

Matthias

On 17 Feb 2010, at 00:58, Fernando Cucchietti wrote:

Hello,

I probably know the answer to this already, but just wanted to check: I would like to use the Montecarlo code to simulate a system with a Hamiltonian that has the Sy operator, that is Sy=-I/2(Splus-Sminus). The worm and sse codes return a runtime error "can not convert complex number into real one". If I don't include de I constant (or (0.,1.) ) in the model.xml file the code starts, but then complains that it cannot simulate this term (which without the complex unit is non-Hermitian). I cannot rotate my basis because I also have the Sx operator, so I am stuck with Sy. Is there a way to do this? It looks like a no-no...

Thanks Fernando

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Fernando Cucchietti Research Fellow ICFO-Institut de Ciencies Fotoniques Mediterranean Technology Park Av. Canal Olimpic s/n 08860 Castelldefels (Barcelona), Spain ============================== 1+1=3, for large values of 1

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