Hi all

It looks like that one can simulate this model with ferromagnetic coupling (the message returned saying that the model has a negative sign if one uses antiferromagnetic coupling). I would like to study magnetization density as a function of external field using loop (since dirloop_sse says that the dirloop_sse for simulating the model is not implemented). Somehow non of the observables look reasonable.... So which observable should I look into in order to study the external field dependence of magnetization density. Thanks.

--- On Thu, 1/13/11, Kubila <kubila@yahoo.com> wrote:

From: Kubila <kubila@yahoo.com>
Subject: Re: [ALPS-users] quantum XY model with an uniform magnetic field in the x-direction
To: comp-phys-alps-users@lists.phys.ethz.ch
Date: Thursday, January 13, 2011, 5:26 AM

Hi Prof. Troyer

   With antiferromagnetic couplings.



--- On Thu, 1/13/11, Matthias Troyer <troyer@phys.ethz.ch> wrote:

From: Matthias Troyer <troyer@phys.ethz.ch>
Subject: Re: [ALPS-users] quantum XY model with an uniform magnetic field in the x-direction
To: comp-phys-alps-users@lists.phys.ethz.ch
Date: Thursday, January 13, 2011, 2:44 AM

With ferromagnetic or antiferromagnetic couplings?

On Jan 13, 2011, at 11:33 AM, Kubila wrote:

Hi ALPS users

   I was wondering can one use looper to simulate quantum XY model with an uniform magnetic field in the x-direction. Thanks.