The dirloop SSE code cannot do fermionic models because the sign problem would be horribly bad

On Sep 8, 2013, at 3:05, Tao Ying <taoying86@gmail.com> wrote:

Dear developers,

I want to simulate the fermion Hubbard model using dirloop_sse, how can I write the parameter file? I did the following:

   LATTICE="square lattice";

   L=8;

   W=8;

   MODEL="fermion Hubbard";

   U    = 5.0;

   V    = 0.0;

   t   = 1.0;

   T = 0.05;

   SWEEPS=2000;

   THERMALIZATION=5000;

   { mu=0.0; }

Then an error occured: Cannot convert fermionic operator to a bosonic matrix. What's wrong with it? If I want to measure the structure factor or correlation function, do I need to add the following in the parameter file?

 REPRESENTATION="SSE";

 MEASURE[Correlations]=true;

 MEASURE[Structure Factor]=true;

 MEASURE[Green Function]=true;

Best,

TaoYing

--

Tao Ying,

Ph.D candidate,

Physics department

Harbin Institute of Technology