Thanks for your reply! Is there any QMC code on ALPS can do the fermion Hubbard model?

Best, TaoYing

2013/9/8 Matthias Troyer troyer@phys.ethz.ch

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

Thank you very much!

2013/9/8 Matthias Troyer troyer@phys.ethz.ch

You can look at the DMFT codes if you want a DMFT solution of the Hubbard model. Simulating the Hubbard model is still very hard because of the sign problem and you need large supercomputers to get reliable results

Matthias

On Sep 8, 2013, at 8:53 AM, Tao Ying taoying86@gmail.com wrote:

Thanks for your reply! Is there any QMC code on ALPS can do the fermion Hubbard model?

Best, TaoYing

2013/9/8 Matthias Troyer troyer@phys.ethz.ch

...

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

-- Tao Ying, Ph.D candidate, Physics department Harbin Institute of Technology