Re: [ALPS-users] BONDOPERATOR measurement question

-- Sebastian Huber Department of Condensed Matter Physics The Weizmann Institute of Science 76100 Rehovot Web: http://www.weizmann.ac.il/~huber Tel: +972 8 934 4258 On 22.11.2011, at 01:11, Matthias Troyer wrote: > Try not to use a minus (-) in the operator name, but instead an underscore or similar > > > On 22 Nov 2011, at 00:09, Sebastian Huber wrote: > >> Dear all, >> >> I have an inhomogeneous lattice problem and I try to measure a "local" bondoperator, e.g., the current over one bond only. I get the following error from the sparsediag application >> >> Did not parse to end of string '(one-bond)/4(i)' >> >> when I try to do a "MEASURE_AVERAGE". I get no error if I use "MEASURE_LOCAL". I am a bit puzzled that "MEASURE_LOCAL" does something all together as my operator contains more than one site, which is in violation to a condition on local measurements on the alps webpage. I paste a minimal (silly) set of configuration files which produces this error below. Help would be greatly appreciated. >> >> Sebastian >> >> lanczosconf: >> >> MODEL="simple"; >> LATTICE="2x2" >> LATTICE_LIBRARY="graph.xml" >> MODEL_LIBRARY="model.xml" >> COMPLEX=true; >> t=-1; >> Nup_total=1; >> Ndown_total=1; >> CONSERVED_QUANTUMNUMBERS="N,Sz"; >> NUMBER_EIGENVALUES=2; >> TRANSLATION_SYMMETRY=false; >> MEASURE_AVERAGE[one-bond]=one-bond; >> {U=1;} >> >> >> graph.xml: >> >> <LATTICES> >> >> <GRAPH name="2x2" dimension="2" vertices="4" edges="9"> >> <VERTEX id="1" type="0"><COORDINATE>0 0</COORDINATE></VERTEX> >> <VERTEX id="2" type="0"><COORDINATE>1 0</COORDINATE></VERTEX> >> <VERTEX id="3" type="0"><COORDINATE>0 1</COORDINATE></VERTEX> >> <VERTEX id="4" type="0"><COORDINATE>1 1</COORDINATE></VERTEX> >> <EDGE source="1" target="2" id="1" type="1" vector="1 0"/> >> <EDGE source="2" target="1" id="2" type="2" vector="1 0"/> >> <EDGE source="3" target="4" id="3" type="3" vector="1 0"/> >> <EDGE source="4" target="3" id="4" type="4" vector="1 0"/> >> <EDGE source="1" target="3" id="5" type="5" vector="0 1"/> >> <EDGE source="2" target="4" id="6" type="6" vector="0 1"/> >> <EDGE source="3" target="1" id="7" type="7" vector="0 1"/> >> <EDGE source="4" target="2" id="8" type="8" vector="0 1"/> >> <EDGE source="1" target="4" id="9" type="9" vector="1 1"/> >> </GRAPH> >> >> </LATTICES> >> >> >> model.xml >> >> <MODELS> >> <SITEBASIS name="fermion"> >> <QUANTUMNUMBER name="Nup" min="0" max="1" type="fermionic"/> >> <QUANTUMNUMBER name="Ndown" min="0" max="1" type="fermionic"/> >> <OPERATOR name="Splus" matrixelement="1/2"> >> <CHANGE quantumnumber="Nup" change="1"/> >> <CHANGE quantumnumber="Ndown" change="-1"/> >> </OPERATOR> >> <OPERATOR name="Sminus" matrixelement="1/2"> >> <CHANGE quantumnumber="Nup" change="-1"/> >> <CHANGE quantumnumber="Ndown" change="+1"/> >> </OPERATOR> >> <OPERATOR name="Sz" matrixelement="(Nup-Ndown)/2"/> >> <OPERATOR name="Nup" matrixelement="Nup"/> >> <OPERATOR name="Ndown" matrixelement="Ndown"/> >> <OPERATOR name="c_down" matrixelement="1"> >> <CHANGE quantumnumber="Ndown" change="-1"/> >> </OPERATOR> >> <OPERATOR name="cdag_down" matrixelement="1"> >> <CHANGE quantumnumber="Ndown" change="1"/> >> </OPERATOR> >> <OPERATOR name="c_up" matrixelement="1"> >> <CHANGE quantumnumber="Nup" change="-1"/> >> </OPERATOR> >> <OPERATOR name="cdag_up" matrixelement="1"> >> <CHANGE quantumnumber="Nup" change="1"/> >> </OPERATOR> >> <OPERATOR name="n" matrixelement="Nup+Ndown"/> >> <OPERATOR name="n_up" matrixelement="Nup"/> >> <OPERATOR name="n_down" matrixelement="Ndown"/> >> </SITEBASIS> >> >> <BASIS name="fermion"> >> <SITEBASIS ref="fermion"/> >> <CONSTRAINT quantumnumber="Nup" value="Nup_total"/> >> <CONSTRAINT quantumnumber="Ndown" value="Ndown_total"/> >> </BASIS> >> >> <BONDOPERATOR name="one-bond" source="1" target="2"> >> I*(cdag_up(1)*c_up(2)-cdag_up(2)*c_up(1)) >> </BONDOPERATOR> >> >> <HAMILTONIAN name="simple"> >> <PARAMETER name="U" default="1"/> >> <BASIS ref="fermion"/> >> <SITETERM site="i"> >> U*n_up(i)*n_down(i) >> </SITETERM> >> </HAMILTONIAN> >> >> </MODELS> >> >> -- >> Sebastian Huber >> Department of Condensed Matter Physics >> The Weizmann Institute of Science >> 76100 Rehovot >> >> Web: http://www.weizmann.ac.il/~huber >> Tel: +972 8 934 4258 >> >