Dear Kublia,
By default, the looper does not calculate quantities related to the transverse magnetization. But, in your case it is straightforward to measure the Zeeman energy just by counting the number of site operators. And then you can extract the transverse magnetization easily.
Which version of looper are you using? The one in the ALPS Applications 1.3.x or the one shipped together with ALPS 2.0?
Best, Synge
On 2011/02/09, at 6:18, Kubila wrote:
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.