Hi,all This is my interpretation of the relationship between vertex, edge and operator. Am I right? Considering 1D Kondo-Heisenberg model, for example: (1) I shall have two types of vertices - spin and fermion; (2) Three types of edges - fermion to fermion, fermion to spin and spin to spin (considering superexchange interaction between spins); (3) For operators, I shall have - type0 fermion_hop(i,j) related to fermion to fermion edge, type1 exchange(i,j) related to fermion to spin (Kondo-exchange interaction) and type2 exchange(i,j) (superexchange); If I am right, does that mean the number of types of bond operators should be the same as the number of types of edges defined in the unitcell?
The other question is: in the unitcell of this simple 1D Kondo-Heisenberg model, I have two-type vertices and three different types of edges, but I do not define the coordinates as your online example "A complex example" in section "How to specify graphs corresponding to a lattice with a unit cell", then is the unitcell which I define 1D or 2D? I think it is 2D, am I right?
Bo-Nan
On Mar 4, 2013, at 5:08, Bo-Nan JIANG bonanjiang@gmail.com wrote:
Hi,all This is my interpretation of the relationship between vertex, edge and operator. Am I right? Considering 1D Kondo-Heisenberg model, for example: (1) I shall have two types of vertices - spin and fermion; (2) Three types of edges - fermion to fermion, fermion to spin and spin to spin (considering superexchange interaction between spins); (3) For operators, I shall have - type0 fermion_hop(i,j) related to fermion to fermion edge, type1 exchange(i,j) related to fermion to spin (Kondo-exchange interaction) and type2 exchange(i,j) (superexchange); If I am right, does that mean the number of types of bond operators should be the same as the number of types of edges defined in the unitcell?
Yes
The other question is: in the unitcell of this simple 1D Kondo-Heisenberg model, I have two-type vertices and three different types of edges, but I do not define the coordinates as your online example "A complex example" in section "How to specify graphs corresponding to a lattice with a unit cell", then is the unitcell which I define 1D or 2D? I think it is 2D, am I right?
No, still 1D since you will have a 1 d chain of unit cells.
Bo-Nan
Stay foolish,Stay hungry.
Dear all,
Is it possible to measure S^2 in ALPS ED for the Hubbard model?
I define S^2 in two different ways, one as 'pm'
<SITEOPERATOR name="pm" site="x"> Splus(x)*Sminus(x)+Sz(x)*Sz(x)-Sz(x) </SITEOPERATOR>
and another as 'mp'
<SITEOPERATOR name="mp" site="x"> Sminus(x)*Splus(x)+Sz(x)*Sz(x)+Sz(x) </SITEOPERATOR>
and measurements gives different results, though they should be the same. At the moment, I cannot understand where is the problem.
Thanks for any comments, Volodymyr Derzhko
comp-phys-alps-users@lists.phys.ethz.ch