Hi,

The message you get below indicates that the looper code will not work for such models.

Matthias

On 17 Oct 2015, at 14:16, Saeed S. Jahromi saeed.s.jahromi@gmail.com wrote:

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/ http://wistaria.comp-phys.org/alps-looper/ copyright (c) 1997-2010 by Synge Todo wistaria@comp-phys.org mailto:wistaria@comp-phys.org

using ALPS/parapack scheduler a Monte Carlo scheduler for multiple-level parallelization copyright (c) 1997-2013 by Synge Todo wistaria@comp-phys.org mailto:wistaria@comp-phys.org

based on the ALPS libraries version 2.2.b3 available from http://alps.comp-phys.org/ 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 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 http://www.saeedjahromi.com/