March 2009 - Comp-phys-alps-users

again local measurements
by Jakub Zakrzewski 18 Mar '09

18 Mar '09

Hello, I asked once but got little reply. So may be this time .... :-) If I want to get <n_i> in Bose-Hubbard (i-numbers sites) I put MEASURE_LOCAL[density]=n; (either in QMC or diagonalizations or DMRG).. Can I get easily e.g. <n_i^2> without recompiling applications ? Can I get both <n_i> and <n_i^2> from the same run ? Can I get e.g. <n_in_j> ? best wishes Kuba __________________________________________________________________

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Energy Gap
by zhian asadzadeh 17 Mar '09

17 Mar '09

Hi Dear, Thank you for your consideration. My model is anisotropic Ferrimagnetic chain in transverse magnetic field. when I say the result is wrong I mean when I have tried to obtain energy gap for some problems and models which have been solved earlier I saw the result doesn't agree with those earlier results. for example spin one and half-one chain and ferrimagnetic chain and anisotropic ferrimagnetic ladder. Something is not very obvius for me, how DMRG calculate ground state and first exited state from one wave function ?! Thanks, Zhian. On Tue, Mar 17, 2009 at 2:30 PM, <comp-phys-alps-users-request(a)phys.ethz.ch>wrote: > Send Comp-phys-alps-users mailing list submissions to > comp-phys-alps-users(a)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(a)phys.ethz.ch > > You can reach the person managing the list at > comp-phys-alps-users-owner(a)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: > > 1. Re: Energy Gap (Matthias Troyer) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Mon, 16 Mar 2009 12:33:11 -0700 > From: Matthias Troyer <troyer(a)phys.ethz.ch> > Subject: Re: [ALPS-users] Energy Gap > To: comp-phys-alps-users(a)phys.ethz.ch > Message-ID: <43E825E5-7BE3-4EA0-9C2A-20A1FC8C21AF(a)phys.ethz.ch> > Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes > > > On Mar 16, 2009, at 2:01 AM, zhian asadzadeh wrote: > > > Hi All, > > > > I want to calculate energy gap for spin chain with DMRG. I set > > NUM_EIGENVALUES=2 in my parm file but the result which achieved is > > wrong. > > Is it necessary to determine something else for example the sector > > which DMRG work in it? in my problem I dont have any good symmetry > > and I can not easily determine the sector which the first exited > > state is in it. I would be very appreciate if someone could please > > help me. > > > > Thanks, > > Zhian. > > Can you please send more details about your model, or better yet the > input file? An what do you mean exactly by saying that the result is > wrong? > > Matthias > > > > End of Comp-phys-alps-users Digest, Vol 36, Issue 10 > **************************************************** >

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Energy Gap
by zhian asadzadeh 16 Mar '09

16 Mar '09

Hi All, I want to calculate energy gap for spin chain with DMRG. I set NUM_EIGENVALUES=2 in my parm file but the result which achieved is wrong. Is it necessary to determine something else for example the sector which DMRG work in it? in my problem I dont have any good symmetry and I can not easily determine the sector which the first exited state is in it. I would be very appreciate if someone could please help me. Thanks, Zhian.

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Compile error for alps 1.3.4 version
by Guilin Zhuang 15 Mar '09

15 Mar '09

Hi! Platform: Red Hat 3.4.3-9.EL4 GCC: 3.4.3 version C++ Boost: 1.34.0,1.35.0,1.36.0,1.38.0 (all were tried) But it is occur that the same error: ./../src/alps/alea/simplebinning.h:602: error: `it' undeclared (first use this function) ./../src/alps/alea/simplebinning.h:602: error: (Each undeclared identifier is reported only once for each function it appears in.) make[2]: *** [observableset.lo] Error 1 make[2]: Leaving directory `/home/glz/ALPSSource/alps-1.3.4/lib/alps' make[1]: *** [all-recursive] Error 1 make[1]: Leaving directory `/home/glz/ALPSSource/alps-1.3.4/lib' make: *** [all-recursive] Error 1 please help me! Thanks a lot!

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Dimension
by Guilin Zhuang 12 Mar '09

12 Mar '09

Hi,teachers! I am first user of SSE in the ALPS software. I havs a simple but important question: 1, How is the susceptibility of simulation by using the SSE package converted to the susceptibility chi(unit: cm3) from the magnetic experiment? 2, What is the dimension of magnetization strength and field strength? Oe or T? Thanks a lot.

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register
by Muhammad Rofiq 11 Mar '09

11 Mar '09

I'm a Physic students of an University in Indonesia. I would like to learn more about ALPS for my reaserch. but I have some problems with my simulations. Please give me some step to regeister in ALPS community. Thankn's Selalu bersama teman-teman di Yahoo! Messenger. Tambahkan mereka dari email atau jaringan sosial Anda sekarang! http://id.messenger.yahoo.com/invite/

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clustered spin simulations
by Brian Keith 10 Mar '09

10 Mar '09

Hello, I am looking for help in simulating a depleted magnetic rectangle. Normally I would just introduce the depletion term and go but I need more control over where the spinless sites are located. Essentially I want to introduce a bias so that there is a greater chance of spinless sites to be placed next to each other. I want to promote clusters of spinless sites. I was looking through the tutorial to find out how to create lattices brute force to no avail. Is there an easy way to promote these clusters? Or is there at least a way to manually place the spinless sites throughout a lattice? thanks, Brian -- Brian Keith Dept. of Physics Clark University

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Re: [ALPS-users] Comp-phys-alps-users Digest, Vol 36, Issue 5
by zhian asadzadeh 10 Mar '09

10 Mar '09

Hi Because you have 6 different spin you must use the following for your basis and in your parm file you must give them their values such local_S0=1/2, local_S1=1,local_S2=3,local_S4=5 and so on. and for J1=3, J2=4, J3=.. . <BASIS name="spin"> <SITEBASIS ref="spin"> <PARAMETER name="local_spin" value="local_S#"/> <PARAMETER name="local_S#" value="local_S"/> <PARAMETER name="local_S" value="1/2"/> </SITEBASIS> </BASIS> and for bond operators you must use: <BONDTERM source="i" target="j"> <PARAMETER name="J#" default="J"/> J#*exchange(i,j) </BONDTERM> in writing your lattice you must define 3 type edge. (I think it is easy use graph instead of lattice). Mohammad. On Tue, Mar 10, 2009 at 3:30 PM, <comp-phys-alps-users-request(a)phys.ethz.ch>wrote: > Send Comp-phys-alps-users mailing list submissions to > comp-phys-alps-users(a)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(a)phys.ethz.ch > > You can reach the person managing the list at > comp-phys-alps-users-owner(a)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: > > 1. clustered spin simulations (Brian Keith) > 2. Question: model writing (Guilin Zhuang) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Mon, 9 Mar 2009 16:11:25 -0400 > From: Brian Keith <btronk(a)gmail.com> > Subject: [ALPS-users] clustered spin simulations > To: comp-phys-alps-users(a)phys.ethz.ch > Message-ID: > <53f922fd0903091311x44caf6a2v10cd77a6421a174c(a)mail.gmail.com> > Content-Type: text/plain; charset="iso-8859-1" > > Hello, > I am looking for help in simulating a depleted magnetic rectangle. > Normally I would just introduce the depletion term and go but I need more > control over where the spinless sites are located. Essentially I want to > introduce a bias so that there is a greater chance of spinless sites to be > placed next to each other. I want to promote clusters of spinless sites. I > was looking through the tutorial to find out how to create lattices brute > force to no avail. Is there an easy way to promote these clusters? Or is > there at least a way to manually place the spinless sites throughout a > lattice? > > thanks, Brian > > -- > Brian Keith > Dept. of Physics > Clark University >

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Question: model writing
by Guilin Zhuang 10 Mar '09

10 Mar '09

Dear teacher! I am interested in the magnetic simulation by using SSE package. I have a system of the cluster, including six cobalt. The hamiltonian is as follow: H=-2{J1*[ S1*S2 + S4*S5 ] + J2*[ S2*S3 + S6*S5 ] + J3*[ S3*S4 + S1*S6 ]} How do I write the model? I have read the model.xml file in the ALPS software. But the example is almost infinite system, but not isolate system in the file. Please help me!

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Correlation measurment
by zhian asadzadeh 05 Mar '09

05 Mar '09

Hi All, I am going to measure <SxSx>, <SySy> two point correlations with DMRG . Please let me know what i must do or add in the lattice and model files? Thanks, Mohammad.

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