Another question: what does it mean when x = source and y = target? For example you have: op1 = c_dagup(y)* c_up(x) op2 = c_dagdown(y)*c_down(x) and I can also do MEASURE_HALF_CORRELATIONS['op_corr'] = op1:op2. THis will return a measurement x = [i, i+1, j, j+1], y = some value. Does the source x from op1 still corresponds to i and target y from op1 corresponds to i+1 (and the source x from op2 still corresponds to j and target y from op2 corresponds to j+1)? Regards, Robertson Esperanza On Tue, May 9, 2017 at 8:31 PM, Robertson Esperanza < robbie.esperanza@gmail.com> wrote:

Hello,

Thanks for all the previous help. What I've done so far is measuring correlation functions using site opertors, now I'm dealing with bond operators. For mps_optim, it seems that i can only measure correlations between single-term bond operators. For example: op1 = c_dagup(x)* c_up(y) op2 = c_dagdown(x)*c_down(y) and I can do MEASURE_HALF_CORRELATIONS['op_corr'] = op1:op2. From the results, it seems that it returns x = [i, i+1, j, j+1], y = some value

I am dealing with a 10 site chain, but i only got results (for i=0) j= 2,...,8. How can i calculate the same correlation functions for j = 0, 1, and 9?

Regards, Robbie