On Fri, 23 Jan 2009 12:00:04 +0100, comp-phys-alps-users-request wrote
> 2. uniform susceptibility (Tadeusz Wasiutynski)
> Message: 2
> Date: Thu, 22 Jan 2009 12:55:44 +0100
> From: "Tadeusz Wasiutynski" <Tadeusz.Wasiutynski(a)ifj.edu.pl>
> Subject: [ALPS-users] uniform susceptibility
> To: comp-phys-alps-users(a)phys.ethz.ch
> Message-ID: <20090122115137.M49749(a)ifj.edu.pl>
> Content-Type: text/plain; charset=iso-8859-2
>
> hello,
> I try to understand all examples in alps-applications. How can I
> figure out what exactly is in the output as "uniform susceptibility"
> (say in Ising) and why it is not simply <M2>-<M>2? In which part of
> the code it is hidden? Tadeusz
>
> ------------------------------
>
> Message: 4
> Date: Thu, 22 Jan 2009 23:10:11 +0900 (JST)
> From: Synge Todo <wistaria(a)comp-phys.org>
> Subject: Re: [ALPS-users] uniform susceptibility
> To: comp-phys-alps-users(a)phys.ethz.ch, Tadeusz.Wasiutynski(a)ifj.edu.pl
> Message-ID: <20090122.231011.245963879.wistaria(a)comp-phys.org>
> Content-Type: Text/Plain; charset=us-ascii
>
> If 'M' means the total uniform magnetization (i.e. M = \sum s_i^z),
> the uniform susceptibility and <M2>-<M>2 differ by the factor \beta/N
> (\beta = 1/T and N the number of sites). If 'M' is the magnetization
> per site (\sum s_i^z / N), then the factor becomes \beta \times N.
>
> Synge
>
Thank you for prompt answer. There is still something unclear for me. When
running spinmc Ising model with say L=8 and T=1, square lattice, update
cluster, sweeps 100000 I get:
Magnetization^2 0.99862084
|Magnetization| 0.999285325
Susceptibility 63.911734
So it looks like Susceptibility=N * Magnetization^2
On the other hand given susceptibility at Tc scales very well with size.
Where do I make mistake?
Tadeusz