Hi Prof. Troyer,
For the model file that I have defined I used
MODEL="kitaev heisenberg" J = 1 Jx = 0 Jy = 0 Jz = 0
and for comparison with the inbuilt spin heisenberg model I used
MODEL="spin" J = 1
Thanks and Regards
Sriluckshmy
On Fri, Aug 15, 2014 at 8:47 AM, Matthias Troyer troyer@phys.ethz.ch wrote:
Can you tell us which coupling parameters you defined for the standard Heisenberg and which ones you defined for your model?
On Aug 14, 2014, at 20:45, Sriluckshmy Viswanathan sriluckus@gmail.com wrote:
Hi Prof. Troyer,
In my model file I have defined a coupling strength J which is same for all the links and coupling strengths Jx, Jy and Jz for tuning the kitaev part which is given below. Setting Jx= Jy=Jz =0 is the standard heisenberg hamiltonian.
<HAMILTONIAN name="kitaev heisenberg"> <PARAMETER name="J" default="1"/> <PARAMETER name="Jz" default="0"/> <PARAMETER name="Jx" default="0"/> <PARAMETER name="Jy" default="0"/> <BASIS ref="spin"/> <BONDTERM source = "i" target="j"> J*Sz(i)*Sz(j) +J*exchange_xy(i,j) </BONDTERM> <BONDTERM type="0" source="i" target="j"> Jz*Sz(i)*Sz(j) + J*Sz(i)*Sz(j) +J*exchange_xy(i,j) </BONDTERM>
<BONDTERM type="1" source="i" target="j"> Jx*Sx(i)*Sx(j) + J*Sz(i)*Sz(j) +J*exchange_xy(i,j) </BONDTERM>
<BONDTERM type="2" source="i" target="j"> Jy*Sy(i)*Sy(j) + J*Sz(i)*Sz(j) +J*exchange_xy(i,j) </BONDTERM> </HAMILTONIAN>
This is where my problem was. this code with these parameters and the inbuilt spin code for heisenberg didnt give the same results in sparse diagonalization and I wanted to know why.
Is this the solution you were mentioning? Please please correct me if I am wrong.
Thanks and Regards
Sriluckshmy
On Fri, Jul 25, 2014 at 8:21 PM, Matthias Troyer troyer@phys.ethz.ch wrote:
The honeycomb lattice definition in the models file has three different edge types:
<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>
and hence you need to separately specify couplings J0, J1 and J2 or Jx0, Jx1 and Jx2 for the three bonds. If you just specify J then all you get is J0, i.e. uncoupled chains
Matthias Troyer
On 22 Jun 2014, at 20:15, Sriluckshmy Viswanathan sriluckus@gmail.com wrote:
Hi,
Thank you so much for your mail. My input for kitaev-heisenberg is LATTICE_LIBRARY="lattices.xml" MODEL_LIBRARY="models.xml"
MODEL="kitaev heisenberg" LATTICE="honeycomb lattice"
local_S = 0.5 W=3 J = 1 Jx = 0 Jy = 0 Jz = 0 {L=3;}
though i havnt changed the lattices.xml file. And for the spin
MODEL="spin" LATTICE="honeycomb lattice"
local_S = 0.5 W=3 J = 1 {L=3;}
Regards
Sriluckshmy
On Mon, Jun 23, 2014 at 4:37 AM, Matthias Troyer troyer@phys.ethz.ch wrote:
Can you send the input files that you used?
On 22 Jun 2014, at 12:03, Sriluckshmy Viswanathan sriluckus@gmail.com wrote:
Hi,
I am writing a code for the computing gap in kitaev-heisenberg model
on the honeycomb lattice using sparse diagonalization. When the coupling for the kitaev term is zero the model patch that I wrote should match the model that is inbuilt. But that doesnt happen. I may have made a mistake in the model patch which is as follows.
<HAMILTONIAN name="kitaev heisenberg"> <PARAMETER name="J" default="1"/> <PARAMETER name="Jz" default="0"/> <PARAMETER name="Jx" default="0"/> <PARAMETER name="Jy" default="0"/> <BASIS ref="spin"/> <BONDTERM source = "i" target="j"> J*Sz(i)*Sz(j) +J*exchange_xy(i,j) </BONDTERM> <BONDTERM type="0" source="i" target="j"> Jz*Sz(i)*Sz(j) + J*Sz(i)*Sz(j) +J*exchange_xy(i,j) </BONDTERM>
<BONDTERM type="1" source="i" target="j"> Jx*Sx(i)*Sx(j) + J*Sz(i)*Sz(j) +J*exchange_xy(i,j) </BONDTERM>
<BONDTERM type="2" source="i" target="j"> Jy*Sy(i)*Sy(j) + J*Sz(i)*Sz(j) +J*exchange_xy(i,j) </BONDTERM> </HAMILTONIAN>
I have also attached the output that I got in dat format. Could you
please help me with this problem?
Sriluckshmy
<kitaev_heisenberg.task1.out.xml.dat><spin.task1.out.xml.dat>
-- Regards Sriluckshmy
-- Regards Sriluckshmy