Hello Rongyang,
Thank you again. With your help, I have checked the graph generated from my lattice definition and corrected my Lattice XML File. But I have a follow-up question that the tunneling rate t' of the second
type bond term does not work.
I can run the simulation without any bug indicated. Then I found the ground energy is the same as when I used the "open chain lattice" with a single tunneling rates t. Next, I deleted the t' in my Parameter XML File. I ran the calculation again and the
ground energy I got was still the same.
I have read the tutorials on ALPS WIKI about the definition of the models. It is said that 'If the lattice contains more than one site per unit-cell, the <BASIS> command should contain one <SITEBASIS> entry for each site of the unit-cell. Each entry should
have a different Type, corresponding to the definitions given in the lattice library file.' (http://alps.comp-phys.org/mediawiki/index.php/Tutorials:ModelHOWTO)
There is only one type of <SITEBASIS> in my Model XML File. Is this the source of the problem?
-----------------------Model XML File--------------------------
<MODELS>
<SITEBASIS name="boson">
<PARAMETER name="Nmax" default="infinity"/>
<QUANTUMNUMBER name="N" min="0" max="Nmax"/>
<OPERATOR name="bdag" matrixelement="sqrt(N+1)">
<CHANGE quantumnumber="N" change="1"/>
</OPERATOR>
<OPERATOR name="b" matrixelement="sqrt(N)">
<CHANGE quantumnumber="N" change="-1"/>
</OPERATOR>
<OPERATOR name="n" matrixelement="N"/>
</SITEBASIS>
<BASIS name="boson">
<SITEBASIS ref="boson"/>
<CONSTRAINT quantumnumber="N" value="N_total/2"/>
</BASIS>
<SITEOPERATOR name="double_occupancy" site="x">
n(x)*(n(x)-1)/2
</SITEOPERATOR>
<BONDOPERATOR name="boson_hop" source="x" target="y">
bdag(x)*b(y)+bdag(y)*b(x)
</BONDOPERATOR>
<HAMILTONIAN name="boson Hubbard">
<PARAMETER name="mu" default="0"/>
<PARAMETER name="t" default="1"/>
<PARAMETER name="t'" default="1"/>
<PARAMETER name="U" default="0"/>
<PARAMETER name="V" default="0"/>
<BASIS ref="boson"/>
<SITETERM site="i">
<PARAMETER name="mu#" default="mu"/>
<PARAMETER name="U#" default="U"/>
-mu#*n(i)+U#*n(i)*(n(i)-1)/2
</SITETERM>
<BONDTERM type="0" source="i" target="j">
-t*boson_hop(i,j)
</BONDTERM>
<BONDTERM type="1" source="i" target="j">
-t'*boson_hop(i,j)
</BONDTERM>
</HAMILTONIAN>
</MODELS>
---------------------END-----------------------------
Is there anything wrong with my Model XML File? How can I solve this problem?
Best,
Yulian