Comp-phys-alps-users

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1248 discussions

Fwd: Help about spin Hamiltonian set up
by Wei Wu 12 Dec '10

12 Dec '10

Dear Sir/Madam, Could you help me with this? I need to define a two-dimensional lattice with canted spin structure. In each chain, we have stronger FM interaction, and weak AFM interaction between chains, and each column has different anisotropic directions one is X and the other is Z, i.e., they are vertical to each. How could I define the lattice and model for this system. I hope I have made clear my question. Looking forward to your reply! Best regards, Wei ---------- Forwarded message ---------- From: Fabien Alet <alet(a)irsamc.ups-tlse.fr> Date: 6 December 2010 14:13 Subject: Re: Help about spin Hamiltonian set up To: Wei Wu <wuwei515(a)googlemail.com> Hi, I suspect that you just have to define a new lattice with two sites per unit cell, and use two different sets of Jx,Jy,Jz for each unit cell. But since I'm not sure exactly what you wish to do, and since this appears to be a generic ALPS question, I suggest you send a (maybe more precise) question to the ALPS users mailing list. comp-phys-alps-users(a)lists.phys.ethz.ch Best Fabien Le 6 déc. 10 à 15:06, Wei Wu a écrit : > Hi, > > Yeah, I mean ALPS. > > Thanks, > Wei > > On 6 December 2010 08:43, ALET Fabien <alet(a)irsamc.ups-tlse.fr> wrote: >> >> Hi, >> >> are you talking about doing this with ALPS, or is it about something else ? >> >> Best >> Fabien >> >> >> On 12/03/2010 08:14 PM, Wei Wu wrote: >>> >>> Dear Dr. Alet Fabien, >>> >>> My name is Wei Wu. I am a postdoc researcher at Imperial College >>> London, UK. I am trying to set up a spin Hamiltonian of spin ladder or >>> coupled spin ladder with canted spins, i.e., the spin easy axes on two >>> legs are different and they are perpendicular to each other. Do you >>> think I can set up a Hamiltonian for this? and if possible, how can I >>> set that up? >>> >>> Many thanks! >>> >>> Best regards, >>> Wei >>> >>> >> >>

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Defining pair correlation for fermions?
by Meng Cheng 04 Dec '10

04 Dec '10

Hi, I'm a new user of ALPS and I have some trouble with defining pair correlations. The problem I'm studying is spin-1/2 fermions in one-dimension. I want to measure the pair correlation, namely the correlation function of c_up(i) c_down(i). I learnt from the ALPS tutorial that to measure the correlation of certain operator I have to define it in "sitebasis" first. Naively I can define the pair operator as <OPERATOR name="pair" matrixelement="1"> <CHANGE quantumnumber="Nup" change="-1"/> <CHANGE quantumnumber="Ndown" change="-1"/> </OPERATOR> and I add this to the definition of sitebasis of "fermion". It seems the only way to implement this operator, but what confuses me is the sign: how do this definition know that c_up and c_down are anti-commuting? It seems to me that the matrixelement can be 1 or -1, depending on how the basis state is defined. So anyone can tell me whether this is the right way to go? Thanks a lot. with all best, Meng Cheng Graduate Research Assistant Department of Physics University of Maryland College Park http://terpconnect.umd.edu/~chmeng

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NUMBER_EIGENVALUES and TOTAL_MOMENTUM (ALPS 2)
by Martin Hohenadler 04 Dec '10

04 Dec '10

Dear all, I was trying to specify the number of eigenvalues calculated by sparsediag, using NUMBER_EIGENVALUES=1 as described here: http://alps.comp-phys.org/mediawiki/index.php/Documentation:sparsediag However, sparsediag nevertheless calculates the lowest eigenvalue for each wavevector. Does this option no longer work? The problem persists even for a simple test case: LATTICE="chain lattice" MODEL="spin" local_S=0.5 Jxy=0.0 Jz="-1.0" Gamma=0.5 NUMBER_EIGENVALUES=1 MEASURE_CORRELATIONS[Diagonal spin correlations]=Sz MEASURE_CORRELATIONS[Offdiagonal spin correlations]="Splus:Sminus" {L=20;} A second question pertains to the output of sparsediag. With the above input file, the results contain the line <PARAMETER name="TOTAL_MOMENTUM">5.7595865315812870833</PARAMETER> However, I have not specified TOTAL_MOMENTUM... Any help is appreciated. Best regards, Martin Hohenadler -- ==================================================== Dr Martin Hohenadler ---------------------------------------------------- Institute for Theoretical Physics and Astrophysics University of Würzburg Am Hubland, 97074 Würzburg ---------------------------------------------------- Tel: +49 (0)151 53506248 (mobile) ---------------------------------------------------- email: martin.hohenadler(a)physik.uni-wuerzburg.de web : www.hohenadler.com ====================================================

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Core parallelization and GPU porting
by degliesposti 03 Dec '10

03 Dec '10

Dear ALPS users, I wonder if some of you is experienced and could give us recent insights about these two points: i) core parallelization with ALPS: which parallel environment is better (OpenMP, MPICH, ...) ii) are there any porting/tests of ALPS on GPU's ? Thanks for your time, Cristian Degli Esposti Boschi

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Questions regarding DMRG
by Chong You Quan 03 Dec '10

03 Dec '10

Hi, I'm using ALPS 1.3.5 on Linux currently. I'm new to ALPS and DMRG and I'd just like to clarify a few questions:1. For full DMRG application with verbose = 1 using the Heisenberg (spin) model, what is the basis of the RHO's eigenvalues in the output? DMRG truncates the density matrix, so, the basis of the density matrix is that of the spin sites is it? For example, L = 2, then the basis would be |00>, |01>, |10>, |11>.. is it correct? What about the basis of the matrix after truncation? Also, if I would like to get the full wavefunction in the basis of the sites, what should I do? Also if I specify that N is conserved, what is the default value of N? Or does it try all possible N to give the lowest energy state?2. I can see that ALPS can be integrated into C++ but I tried googling for examples and documentation to no avail.. Is it in the Trac wiki? If so, must one register for it in order to view the documentation? The default documentation seems to specify what the input valu es represent but don't describe much of the output or how to integrate ALPS into C++.. Am I missing out on some way I can find the documentation for ALPS and how to integrate it in C++?3. I noticed there were some .dat files after running the DMRG application.. Are those temporary files stored during calculation or are those actual output files? I didn't seem to be able to extract any form of data from those files.. Is it that all the useful output for the DMRG is written to the screen?4. I'm not sure why but my parameter2xml does not seem to work on any of the example parameter files.. I'm currently just typing out the xml file by hand. Maybe I'm just missing out on something.. Does parameter2xml output to a specific directory or something?5. Almost all of the files on http://www.comp-phys.org/lugano04/Talks.html seem to be broken.. Is it that the links are outdated or something? I'm sorry if some of these questions sound too amateur but this seems to be the best place I can find an answer to these questions.Thanks in advance. Regards,YQ

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Re: [ALPS-users] ALPS linux binary packages in repositories?
by Ryo IGARASHI 30 Nov '10

30 Nov '10

Dear Prof. Troyer, On Tue, Nov 30, 2010 at 2:59 PM, Matthias Troyer <troyer(a)phys.ethz.ch> wrote: > Regarding lp_solve, we are testing an ALPS replacement for it, so that user do not need to download it in the future. Is implementing own Linear Programming solver easier than updating to lp_solve 5.5? Since Debian/Ubuntu/RHEL all have official lp_solve package (5.5), updating should be enough from the packaging purpose. (See #68 on trac). Best regards, -- Ryo IGARASHI, Ph.D. rigarash(a)hosi.phys.s.u-tokyo.ac.jp OpenPGP fingerprint: BAD9 71E3 28F3 8952 5640 6A53 EC79 A280 6A19 2319

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ALPS linux binary packages in repositories?
by Krunoslav Prsa 30 Nov '10

30 Nov '10

Dear ALPS developers, I have a simple question. Are ALPS binary packages available for download/automatic update through standard Ubuntu/Debian repositories? This appears to be the main argument of the clusters' system administrators against requests to install alps libraries and applications. They claim that it is not possible and that it involves extra work for them to update it manually (which they are not paid for). I also cannot seem to find it in packages.debian.org and packages.ubuntu.com. There are only some old binaries for Ubuntu 6.06 Dapper Drake. The manual installation of ALPS on a cluster without administration privileges is difficult. This needs to be said, although I understand that you are continuously doing steps to make it easier. I think that many end users would appreciate having a standardized way of installing and updating the packages through the repositories. Please note that all this is written bona fide (from a happy ALPS user) and assuming, of course, that this issue is not already resolved. Best wishes and thanks in advance, Kruno ------------------------------------------------- Dr. Krunoslav Prsa, Postdoc Dynamics of strongly correlated materials Lab. for Solid State Physics Building/Office: HPF/E15.1 Schafmattstrasse 16, ETH Zürich Hönggerberg, CH-8093 Switzerland. Office phone: +41 44 633 22 96 Lab phone: +41 44 633 23 01 Mobile phone: +41 76 386 17 99 -------------------------------------------------

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some bugs on the ALPS web site
by Ruben Ghulghazaryan 25 Nov '10

25 Nov '10

Hi, Recently the ALPS web site was updated. It seems the web site http://alps.comp-phys.org/mediawiki/index.php/Tutorials:LatticesAndGraphs contains some language problems. I got some messages like the one below with Firefox 3.6.10 +++++++++ Invalid language. You need to specify a language like this: <source lang="html4strict">...</source> Supported languages for syntax highlighting: 4cs, 6502acme, 6502kickass, 6502tasm, 68000devpac, abap, actionscript, actionscript3, ada, algol68, apache, applescript, apt_sources, asm, asp, autoconf, autohotkey, autoit, avisynth, awk, bash, basic4gl, bf, bibtex, blitzbasic, bnf, boo, c, c_mac, caddcl, cadlisp, cfdg, cfm, chaiscript, cil, clojure, cmake, cobol, cpp, cpp-qt, csharp, css, cuesheet, d, dcs, delphi, diff, div, dos, dot, e, ecmascript, eiffel, email, erlang, f1, fo, fortran, freebasic, fsharp, gambas, gdb, genero, genie, gettext, glsl, gml, gnuplot, go, groovy, gwbasic, haskell, hicest, hq9plus, html4strict, icon, idl, ini, inno, intercal, io, j, java, java5, javascript, jquery, kixtart, klonec, klonecpp, latex, lb, lisp, locobasic, logtalk, lolcode, lotusformulas, lotusscript, lscript, lsl2, lua, m68k, magiksf, make, mapbasic, matlab, mirc, mmix, modula2, modula3, mpasm, mxml, mysql, newlisp, nsis, oberon2, objc, objeck, ocaml, ocaml-brief, oobas, oracle11, oracle8, oxygene, oz, pascal, pcre, per, perl, perl6, pf, php, php-brief, pic16, pike, pixelbender, plsql, postgresql, povray, powerbuilder, powershell, progress, prolog, properties, providex, purebasic, python, q, qbasic, rails, rebol, reg, robots, rpmspec, rsplus, ruby, sas, scala, scheme, scilab, sdlbasic, smalltalk, smarty, sql, systemverilog, tcl, teraterm, text, thinbasic, tsql, typoscript, unicon, vala, vb, vbnet, verilog, vhdl, vim, visualfoxpro, visualprolog, whitespace, whois, winbatch, xbasic, xml, xorg_conf, xpp, z80, zxbasic +++++++++ Regards, Ruben

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ALPS 2.0.0rc2 binary packages for Debian (amd64)
by Ryo IGARASHI 25 Nov '10

25 Nov '10

Hi, I have created binary packages of ALPS 2.0.0rc2 for Debian GNU/Linux (primary for sid(unstable), but should work also on squeeze(testing)). The apt line is as follows: deb http://alps.comp-phys.org/static/software/debian/sid ./ deb-src http://alps.comp-phys.org/static/software/debian/sid ./ Currently, I have only compiled amd64 packages. I can run python-based tutorials with these binary packages[1][2], but if you find any bugs related to debian packaging, please open the trac ticket and assign to me(rigarash) or just report to the ML. [1] Since all binaries/scripts are installed system-wide, use 'python' instead of 'alpspython'. [2] This package does not contain dirloop-sse binary because of the incompatibility of lpsolve library. Best regards, -- Ryo IGARASHI, Ph.D. rigarash(a)hosi.phys.s.u-tokyo.ac.jp OpenPGP fingerprint: BAD9 71E3 28F3 8952 5640 6A53 EC79 A280 6A19 2319

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ALPS 2.0 release candidate
by Matthias Troyer 25 Nov '10

25 Nov '10

Dear all, we finally have an ALPS 2 release candidate available on the Web. The MacOS X 10.5 build will take a bit longer but will also come soon. Please try to use is, install it, check your codes with it and report any bug to the mailing list. We are nearing completion of ALPS 2.0 Matthias Troyer

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Comp-phys-alps-users