Advanced correlation functions - Comp-phys-alps-users

28 Apr 2009


      Hi Dear,
Thank you for your guidance, but the mentioned definition for Sy doesn't
work.
And for the first question, how I can change the code for measuring those
two kind of  correlations? I mean the correlation of first site with others
and middle site with others too.
Thanks,
Zhian.
On Tue, Apr 28, 2009 at 2:30 PM,
comp-phys-alps-users-request@phys.ethz.chwrote:
...
Send Comp-phys-alps-users mailing list submissions to
       comp-phys-alps-users@phys.ethz.ch
To subscribe or unsubscribe via the World Wide Web, visit
       https://webmail.phys.ethz.ch/mailman/listinfo/comp-phys-alps-users
or, via email, send a message with subject or body 'help' to
       comp-phys-alps-users-request@phys.ethz.ch
You can reach the person managing the list at
       comp-phys-alps-users-owner@phys.ethz.ch
When replying, please edit your Subject line so it is more specific
than "Re: Contents of Comp-phys-alps-users digest..."
Today's Topics:

Re: lapack support in ALPS (Synge Todo)
Re: Advanced correlation functions (Justin David Peel)
Re: Comp-phys-alps-users Digest, Vol 37, Issue 18
(Justin David Peel)


Message: 1
Date: Mon, 27 Apr 2009 19:51:14 +0900
From: Synge Todo wistaria@comp-phys.org
Subject: Re: [ALPS-users] lapack support in ALPS
To: comp-phys-alps-users@phys.ethz.ch
Message-ID: 04B17733-4F07-4867-8B22-4343337160BB@comp-phys.org
Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
Dear Fu-Jiun Jiang,
On 2009/04/23, at 23:39, Fu-Jiun Jiang ITP wrote:
...
When install the ALPS with lapack being supported, what command
should be used? In the instruction, it is said
--with-lapack-dir=/path/to/my/lapack/ --with-lapack="-l my_lapack".
Is it true that first one should point to where the lapack library is.
How about the second one? Thanks.
In many cases, lapack installation will be found automatically without
any options.  If this is not the case, please your
system administrator about the linker options to link your program
against lapack.  For example, if you are linking
liblapack.a and libblas.a in /path/to/my/lapack, then the configure
options should be
--with-lapack-dir=/path/to/my/lapack --with-lapack="-llapack -lblas"
Synge

Message: 2
Date: Mon, 27 Apr 2009 11:35:24 -0600
From: Justin David Peel justin.peel@utah.edu
Subject: Re: [ALPS-users] Advanced correlation functions
To: "comp-phys-alps-users@phys.ethz.ch"
       comp-phys-alps-users@phys.ethz.ch
Message-ID:
       <3E5F591958142A40B693A5FC6672D4942624680106@C8V1.xds.umail.utah.edu
...
Content-Type: text/plain; charset="us-ascii"
I'm not sure about only measuring those two correlations (you might have to
change the code for that), but, as to your last question, you should be able
to use Sx:Sx because the Sx operator is defined in the models.xml file in
terms of the raising and lowering operators. If you want to measure Sy, you
would have to add the following lines to the models.xml file:
<SITEOPERATOR name="Sy" site="x">
 1/2*(Splus(x)-Sminus(x))
</SITEOPERATOR>
because it hasn't been defined as far as I can tell.
Good luck,
Justin
________________________________________
From: comp-phys-alps-users-bounces@phys.ethz.ch [
comp-phys-alps-users-bounces@phys.ethz.ch] On Behalf Of zhian asadzadeh [
zhian.asadzadeh@gmail.com]
Sent: Sunday, April 26, 2009 1:54 AM
To: Comp-phys-alps-users@phys.ethz.ch
Subject: [ALPS-users] Advanced correlation functions
Hi All,
I am using DMRG for my problem and I am going to measure diagonal and
offdiagonal correlation functions.
I am interest to obtain the correlation of first site with other sites and
 the middle site with other sites too.
The output of DMRG consist of   all the combinations which are possible but
I just want the two correlations mentioned above because the output will be
very large ( I am studying the ferrimagnetic chain with 100 sites).
can I do that? how?
And also can I use Sx:Sx for measuring off diagonal correlation functions?
Thanks,
Zhian.

Message: 3
Date: Mon, 27 Apr 2009 11:42:56 -0600
From: Justin David Peel justin.peel@utah.edu
Subject: Re: [ALPS-users] Comp-phys-alps-users Digest, Vol 37, Issue
       18
To: "comp-phys-alps-users@phys.ethz.ch"
       comp-phys-alps-users@phys.ethz.ch
Message-ID:
       <3E5F591958142A40B693A5FC6672D4942624680107@C8V1.xds.umail.utah.edu
...
Content-Type: text/plain; charset="us-ascii"
Someone correct me if I'm wrong, but I believe this isn't very directly
feasible. The ground state vector from the exact ground state will be in a
different basis and have a different length than the ground state vector
from DMRG (it's a truncated basis after all).
________________________________________
From: comp-phys-alps-users-bounces@phys.ethz.ch [
comp-phys-alps-users-bounces@phys.ethz.ch] On Behalf Of Gang Chen [
chggst@physics.ucsb.edu]
Sent: Saturday, April 25, 2009 9:55 AM
To: comp-phys-alps-users@phys.ethz.ch
Subject: Re: [ALPS-users] Comp-phys-alps-users Digest, Vol 37, Issue 18
Thanks, I want to compute the overlap between the exact ground state
and the state I generated from other method.
best,
Gang
On Sat, Apr 25, 2009 at 3:00 AM, <
comp-phys-alps-users-request@phys.ethz.chmailto:
comp-phys-alps-users-request@phys.ethz.ch> wrote:
Send Comp-phys-alps-users mailing list submissions to
      comp-phys-alps-users@phys.ethz.chmailto:
comp-phys-alps-users@phys.ethz.ch
To subscribe or unsubscribe via the World Wide Web, visit
      https://webmail.phys.ethz.ch/mailman/listinfo/comp-phys-alps-users
or, via email, send a message with subject or body 'help' to
      comp-phys-alps-users-request@phys.ethz.chmailto:
comp-phys-alps-users-request@phys.ethz.ch
You can reach the person managing the list at
      comp-phys-alps-users-owner@phys.ethz.chmailto:
comp-phys-alps-users-owner@phys.ethz.ch
When replying, please edit your Subject line so it is more specific
than "Re: Contents of Comp-phys-alps-users digest..."
Today's Topics:

extract the ground state from DMRG or Exact       diagonalization
(Gang Chen)
Re: extract the ground state from DMRG or Exact
diagonalization (Justin David Peel)


Message: 1
Date: Fri, 24 Apr 2009 14:57:02 -0700
From: Gang Chen <chggst@physics.ucsb.edumailto:chggst@physics.ucsb.edu>
Subject: [ALPS-users] extract the ground state from DMRG or Exact
      diagonalization
To: comp-phys-alps-users@phys.ethz.chmailto:
comp-phys-alps-users@phys.ethz.ch
Message-ID:
      <3924ab970904241457k17ab51b1tbd002d09ae7287e@mail.gmail.commailto:
3924ab970904241457k17ab51b1tbd002d09ae7287e@mail.gmail.com>
Content-Type: text/plain; charset="iso-8859-1"
Hi All,
If I use DMRG or Exact diagonalization to find the ground state of my
Hamiltonian. How can
I extract the ground state vector (the numerical vector) from my results?
best,
--
GANG CHEN
Department of Physics
University of California
Santa Barbara, CA 93106
Office: Broida 6216
Phone: 805-893-5260
Fax: 805-893-3378