The ALPS models don’t really have a notion about kinetic vs non-kinetic part of the Hamiltonian. What you usually do is to compute parts of the Hamiltonian with local or average measurements.
For example there is already a "fermion_hop” BONDOPERATOR defined like this: <BONDOPERATOR name="fermion_hop" source="x" target="y"> cdag_up(x)*c_up(y)+cdag_up(y)*c_up(x)+cdag_down(x)*c_down(y)+cdag_down(y)*c_down(x) </BONDOPERATOR>
That you can measure with MEASURE_LOCAL[local kinetic] = "fermion_hop" MEASURE_AVERAGE[avg kinetic] = "fermion_hop"
The output of the first measurement will be the hopping strength at every bond defined in the lattice, and the sum of them in the average measurement.
Best regards, Michele
-- ETH Zurich Michele Dolfi Institute for Theoretical Physics HIT G 32.4 Wolfgang-Pauli-Str. 27 8093 Zurich Switzerland
dolfim@phys.ethz.ch www.itp.phys.ethz.ch
+41 44 633 78 56 phone +41 44 633 11 15 fax
On Feb 9, 2016, at 8:54 AM, 北尘心 740572900@qq.com wrote:
Dear all, I am trying to compute the kinetic energy in the hubbard model by means of mps or dmrg code .Can mps or dmrg code measure it directly?If it can, how should I set in model and custom measurements ?
Yours sincerely,
Xingbo Wei Zhejiang Normal Universtiy, Jinhua, 230014, China