October 2015 - Comp-phys-alps-users

About the stiffness in Direct loop QMC
by 郭怀明 20 Dec '15

20 Dec '15

Dear All, I have a question about the stiffness measured in direct loop QMC. I consider hard-core bosons, when the stiffness is the superfluid. I find its defination: <W^2_x+W^2_y>/2t\beta L, where W_x(y) is the winding number along the x or y direction. Suppose I have square lattice. If next nearest neighbor hopping is included with amplitude t', is its contribution is included in the code? Also if the lattice is two-leg ladder with NN and NNN hopping (the amplitudes are t and t'), the superfluid is along one direction. Is the contribution from the NN and NNN hoppings included? Sincerely, Huaiming Guo

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About the measurement in direct loop QMC
by 郭怀明 20 Dec '15

20 Dec '15

Dear all, I want to ask a question about the measurement in direct loop QMC. 1: can we use "Measure[Bond type stiffness]=True " for hardcore bosons? Since I use it, no result is returned. 2: If I use " MEAURE_FACTOR[Name]="n" " to measure the stucture factor, the error appears. Does QMC not support such expression? 3: When I measure the structure factor, are the structure factor with all possible momentum provided? Can I specify the wanted momentum, such as: 2\pi/3 for 1D? Thank you very much. Sincerely, Huaiming Guo

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Install ALPS on Windows x64
by Tao Ying 04 Nov '15

04 Nov '15

Dear all, I'm trying to install ALPS to "C:\Program Files\ALPS" on Windows x64.But there is something wrong: "Warning! PATH too long installer unable to modify PATH". How can I deal with this problem? Best regards, Tao Ying -- Tao Ying, Lecturer in department of physics, Harbin Institute of Technology

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ALPS and pycharm
by Salvatore Lorenzo 25 Oct '15

25 Oct '15

Dear All, i have compiled ALPS from source, and it is all ok. Now i would use it with pycharm, but the output of “import pyalps” is Could not find platform independent libraries <prefix> Could not find platform dependent libraries <exec_prefix> Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>] ImportError: No module named site Can you help me? Thanks anyway. Salvatore Lorenzo

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Re: [ALPS-users] QMC of Bose-Hubbard model with NNN interaction
by taoying86 24 Oct '15

24 Oct '15

Great answer! Thanks Huaiming! Best,Tao Ying -------- 原始邮件 -------- 发件人： hmguo <hmguo(a)buaa.edu.cn> 日期: 2015-10-24 01:55 (GMT+01:00) 收件人： comp-phys-alps-users <comp-phys-alps-users(a)lists.phys.ethz.ch> 主题： Re: [ALPS-users] QMC of Bose-Hubbard model with NNN interaction hello,Tao, I think you should define the nnn bonds in the lattice.xml and use different type. Then in bond term, you use type to distinguish then,I.e., bondterm type="1", the other remains the same. huaiming 在 2015-10-24 03:21:51，"Tao Ying" <taoying86(a)gmail.com> 写道： >Dear all, > > >I want to use QMC in ALPS to simulate Bose-Hubbard model with NNN interaction, we know for NN interaction V, we can define V as following: > <BONDTERM source="i" target="j"> > <PARAMETER name="V" default="0"/> > V*n(i)*n(j) > </BONDTERM> > > >Now I want to include NNN interaction, how can I define it? (source="i" target="?") > > >Best regards, >Tao Ying > > >-- > >Tao Ying, >Lecturer in department of physics, >Harbin Institute of Technology

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QMC of Bose-Hubbard model with NNN interaction
by Tao Ying 24 Oct '15

24 Oct '15

Dear all, I want to use QMC in ALPS to simulate Bose-Hubbard model with NNN interaction, we know for NN interaction V, we can define V as following: <BONDTERM source="i" target="j"> <PARAMETER name="V" default="0"/> V*n(i)*n(j) </BONDTERM> Now I want to include NNN interaction, how can I define it? (source="i" target="*?*") Best regards, Tao Ying -- Tao Ying, Lecturer in department of physics, Harbin Institute of Technology

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The problem of measuring stiffness in QMC with defining lattice using graph
by 郭怀明 20 Oct '15

20 Oct '15

Dear All, For the lattice in alps, we can use <LATTICES> <GRAPH>, in which can define an arbitrary lattice. However I find when I use this way, the stiffness measured in QMC is always zero. I wonder how to fix it. Thank you very much. Sincerely, Huaiming Guo

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MPS
by Huaiming Guo 19 Oct '15

19 Oct '15

Dear All, I try the example script provided by alps. But the following information shows that there is an error. I attach the spin_one.py, which can also be found in the alps. What is the problem? Thank you very much. Sincerely, Huaiming Guo C:\alpsproject\mps>vispython spin_one.py C:\alpsproject\mps>REM Copyright Matthias Troyer 2010-2013. C:\alpsproject\mps>REM Distributed under the Boost Software License, Version 1. 0. C:\alpsproject\mps>REM (See accompanying file LICENSE_1_0.txt or copy at C:\alpsproject\mps>REM http://www.boost.org/LICENSE_1_0.txt) C:\alpsproject\mps>IF EXIST C:\"Program Files"\VisTrails\Python27\python.exe C:\ "Program Files"\VisTrails\Python27\python.exe spin_one.py C:\alpsproject\mps>IF EXIST C:\"Program Files"\VisTrails\Python27_64\python.exe C:\"Program Files"\VisTrails\Python27_64\python.exe spin_one.py mps_optim parm_spin_one.in.xml --write-xml Traceback (most recent call last): File "spin_one.py", line 57, in <module> for s in data[0]: IndexError: list index out of range C:\alpsproject\mps>IF EXIST C:\"Program Files (x86)"\VisTrails\Python27\python.e xe C:\"Program Files (x86)"\VisTrails\Python27\python.exe spin_one.py C:\alpsproject\mps>IF EXIST C:\"Program Files"\VisTrails\vistrails\Python27\pyth on.exe C:\"Program Files"\VisTrails\vistrails\Python27\python.exe spin_one.py C:\alpsproject\mps>IF EXIST C:\"Program Files"\VisTrails\vistrails\Python27_64\p ython.exe C:\"Program Files"\VisTrails\vistrails\Python27_64\python.exe spin_one .py C:\alpsproject\mps>IF EXIST C:\"Program Files (x86)"\VisTrails\vistrails\Python2 7\python.exe C:\"Program Files (x86)"\VisTrails\vistrails\Python27\python.exe sp in_one.py

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Question on collect_result
by Leo Fang 19 Oct '15

19 Oct '15

Hello, Recently I am trying to understand how the hybridization qmc solver is implemented. In line 89 of the file hybmain.cpp, I noticed that the function "collect_result" is called and the returned stuff is assigned to a variable called"results". I know "results" is an "alps::results_type<hybridization>::type" object, aka an accumulator. What I don't understand is its data structure (how elements are stored and how to access them). For example, I find the usage of "results["Sign"]", "results[order_name.str()]", etc in hybevaluate.cpp confusing, because it doesn't seem to me that the accumulator stores information in the std::map type. Can someone explain it to me or point me to relevant documentation (if any), please? Thanks. Sincerely, Leo (Fang Yao-Lung) Duke Physics

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XYZ interaction in alps-looper algorithm
by Saeed S. Jahromi 17 Oct '15

17 Oct '15

Dear All, I am trying to run the QMC "loop" code for the Kitaev honeycomb model which is actually an XYZ two-spin interaction on a honeycomb lattice with three different link types i.e. x,y and z. *The parameter file that I use is defined as:* parms = [] for t in [0.05, 0.1, 0.2, 0.3]: parms.append( { 'LATTICE' : "honeycomb kitaev lattice", 'T' : t, 'Jx' : .1 , 'Jz' : .1 , 'Jy' : .1 , 'ALGORITHM' : "loop", 'THERMALIZATION' : 65536/8, 'SWEEPS' : 65536, 'MODEL' : "K-H", 'L' : 4 } ) *The model that I use is defined as: * <HAMILTONIAN name="K-H"> <PARAMETER name="Jz" default="0"/> <PARAMETER name="Jx" default="0"/> <PARAMETER name="Jy" default="0"/> <PARAMETER name="hx" default="0"/> <PARAMETER name="hz" default="0"/> <BASIS ref="spin"/> <SITETERM site="i"> -hz*Sz(i)-hx*Sx(i) </SITETERM> <BONDTERM type="0" source="i" target="j"> Jz*Sz(i)*Sz(j) </BONDTERM> <BONDTERM type="1" source="i" target="j"> Jx*Sx(i)*Sx(j) </BONDTERM> <BONDTERM type="2" source="i" target="j"> Jy*Sy(i)*Sy(j) </BONDTERM> </HAMILTONIAN> *and the lattice is defined as**:* <UNITCELL name="honeycomb inhomogeneous" dimension="2"> <VERTEX><COORDINATE>0 0</COORDINATE></VERTEX> <VERTEX><COORDINATE>-0.288665771484375 0.5773468017578125</COORDINATE></VERTEX> <EDGE type="0"><SOURCE vertex="1"/><TARGET vertex="2"/></EDGE> <EDGE type="1"><SOURCE vertex="2"/><TARGET vertex="1" offset="0 1"/></EDGE> <EDGE type="2"><SOURCE vertex="1"/><TARGET vertex="2" offset="1 -1"/></EDGE> </UNITCELL> <LATTICEGRAPH name = "honeycomb kitaev lattice"> <FINITELATTICE> <LATTICE ref="triangular lattice"/> <PARAMETER name="W" default="L"/> <EXTENT dimension="1" size="L"/> <EXTENT dimension="2" size="W"/> <BOUNDARY type="periodic"/> </FINITELATTICE> <UNITCELL ref="honeycomb inhomogeneous"/> </LATTICEGRAPH> *when I run the simulation with the "loop" code, the following message is produced and the simulation stops:* multi-cluster quantum Monte Carlo algorithms for spin systems available from http://wistaria.comp-phys.org/alps-looper/ copyright (c) 1997-2010 by Synge Todo <wistaria(a)comp-phys.org> using ALPS/parapack scheduler a Monte Carlo scheduler for multiple-level parallelization copyright (c) 1997-2013 by Synge Todo <wistaria(a)comp-phys.org> based on the ALPS libraries version 2.2.b3 available from http://alps.comp-phys.org/ copyright (c) 1994-2013 by the ALPS collaboration. Consult the web page for license details. For details see the publication: B. Bauer et al., J. Stat. Mech. (2011) P05001. [2015-Oct-17 14:46:49]: starting scheduler on jahromi-Sharif master input file = /home/jahromi/Desktop/MyComputations/ALPS/Looper/parmlooper.in.xml master output file = /home/jahromi/Desktop/MyComputations/ALPS/Looper/parmlooper.out.xml termination file = [disabled] total number of thread(s) = 1 thread(s) per clone = 1 number of thread group(s) = 1 auto evaluation = yes time limit = unlimited interval between checkpointing = 3600 seconds interval between progress report = 600 seconds interval between vmusage report = infinity task range = all worker dump format = hdf5 worker dump policy = running workers only [2015-Oct-17 14:46:49]: task status: total number of tasks = 4 new = 4, running = 0, continuing = 0, suspended = 0, finished = 0, completed = 0, skipped = 0 [2015-Oct-17 14:46:49]: starting 1 threadgroup(s) [2015-Oct-17 14:46:49]: dispatching a new clone[1,1] on threadgroup[1] (Jx+Jy) and (Jx-Jy) may not have opposite signs FYI, I have enable the xyz bond support as instructed in this link and recompiled alps. https://lists.phys.ethz.ch/pipermail/comp-phys-alps-users/2013/002282.html I also tested the algorithm for the "XYZ spin" model available on the alps-looper source on wistaria GitHub and the results is the same and the problem exist there, either. I would be so thankful if you could help me on this matter Best -- Saeed S. Jahromi ========================================================== Postdoctoral Researcher Physics Department, Sharif University of Technology P.O. Box 11155-9161, Tehran , Iran. Mailing Adrress: Azadi Ave., 14588-89694, Tehran, Iran Homepage: http://www.saeedjahromi.com ==========================================================

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