my question about current correlation function with fulldiag and sparsediag remains unanswered --- On Fri, 2/27/09, comp-phys-alps-users-request@phys.ethz.ch <comp-phys-alps-users-request@phys.ethz.ch> wrote:

From: comp-phys-alps-users-request@phys.ethz.ch <comp-phys-alps-users-request@phys.ethz.ch> Subject: Comp-phys-alps-users Digest, Vol 35, Issue 8 To: comp-phys-alps-users@phys.ethz.ch Date: Friday, February 27, 2009, 4:00 PM Send Comp-phys-alps-users mailing list submissions to     comp-phys-alps-users@phys.ethz.ch

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Today's Topics:

   1. current correlation function for fermionic hubbard    model       (khalid hassan)    2. Re: current correlation function for fermionic hubbard model       (Adrian E. Feiguin)    3. current correlation function for fermionic hubbard    model       using alps (khalid hassan)

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Message: 1 Date: Thu, 26 Feb 2009 13:25:11 -0800 (PST) From: khalid hassan <mkhloane@yahoo.com> Subject: [ALPS-users] current correlation function for fermionic     hubbard    model To: comp-phys-alps-users@phys.ethz.ch Message-ID: <826945.64034.qm@web59410.mail.ac4.yahoo.com> Content-Type: text/plain; charset=us-ascii

Can alps can calculate the current correlation function for the fermionic hubbard model model for say two site. I have been using alps to calculate cahrge coorelation function

the charge correlation function is

< n_i n_j > = < c_i^+ c_i  c_i^+ c_i >

where as the current correlation function is

< j_i j_j > = < c_i^+ c_j  c_k^+ c_l >

see the changing indexes.

If it is possible then send me the program statement

Best regards

Khalid Loane

     

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Message: 2 Date: Thu, 26 Feb 2009 14:19:05 -0800 From: "Adrian E. Feiguin" <afeiguin@kitp.ucsb.edu> Subject: Re: [ALPS-users] current correlation function for fermionic     hubbard model To: comp-phys-alps-users@phys.ethz.ch Message-ID: <49A71559.80403@kitp.ucsb.edu> Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Hi Khalid,

Are you using exact diagonalization, or DMRG?

At the present, it hasn't been implemented in the DMRG code.

Saludos, <ADRIAN>

khalid hassan wrote:

...

Can alps can calculate the current correlation function for the fermionic hubbard model model for say two site. I have been using alps to calculate cahrge coorelation function

the charge correlation function is

< n_i n_j > = < c_i^+ c_i  c_i^+ c_i

where as the current correlation function is

< j_i j_j > = < c_i^+ c_j  c_k^+ c_l

see the changing indexes.

If it is possible then send me the program statement

Best regards

Khalid Loane

     

 

------------------------------

Message: 3 Date: Fri, 27 Feb 2009 01:28:00 -0800 (PST) From: khalid hassan <mkhloane@yahoo.com> Subject: [ALPS-users] current correlation function for fermionic     hubbard    model using alps To: comp-phys-alps-users@phys.ethz.ch Message-ID: <976367.6290.qm@web59408.mail.ac4.yahoo.com> Content-Type: text/plain; charset=us-ascii

I am using alps for the calculation of charge correlation function for the fermionic hubbard model. Now I want to calculate the current correlation function.

the expression for the charge correlation function is

< n_i : n_j >   =  < c_i^+ c_i : c_j^+ c_j >

the expression for the current correlation function is

< j_i : j_j >   =  < c_i^+ c_j : c_k^+ c_l >

Notice the changing indices in the current expression.

If it is possible then please give the program statements doing this

Best Regards

Khalid Loane

     

End of Comp-phys-alps-users Digest, Vol 35, Issue 8 ***************************************************