SpinlessFermions.h

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#ifndef STRAWBERRY_SpinlessFermions
#define STRAWBERRY_SpinlessFermions
 
#include "symmetry/U0.h"
#include "models/SpinlessFermionsU1.h"
#include "models/SpinlessFermionsZ2.h"
 
namespace VMPS
{
 
class SpinlessFermions : public Mpo<Sym::U0>, public SpinlessFermionsObservables<Sym::U0>, public ParamReturner
{
public:
    typedef Sym::U0 Symmetry;
    MAKE_TYPEDEFS(SpinlessFermions)
    
private:
    typedef typename Symmetry::qType qType;
    
public:
    
    SpinlessFermions() : Mpo<Symmetry>(), SpinlessFermionsObservables(), ParamReturner(SpinlessFermions::sweep_defaults) {};
    SpinlessFermions (const size_t &L, const vector<Param> &params);
    
    static qarray<0> singlet (int N) {return qarray<0>{};};
    static constexpr MODEL_FAMILY FAMILY = SPINLESS;
    
    template<typename Symmetry_>
    static void add_operators (const std::vector<SpinlessFermionBase<Symmetry_> > &B, const ParamHandler &P, HamiltonianTermsXd<Symmetry_> &Terms);
    
    static const std::map<string,std::any> defaults;
    static const std::map<string,std::any> sweep_defaults;
};
 
const std::map<string,std::any> SpinlessFermions::defaults = 
{
    {"t",1.}, {"Delta",0.}, {"tPrime",0.},
    {"V",0.}, {"Vph",0.},
    {"Vprime",0.}, {"VphPrime",0.},
    {"mu",0.},{"t0",0.},
    {"D",2ul}, {"CALC_SQUARE",true}, {"CYLINDER",false}, {"OPEN_BC",true}, {"Ly",1ul}, 
};
 
const std::map<string,std::any> SpinlessFermions::sweep_defaults = 
{
    {"max_alpha",100.}, {"min_alpha",1.e-11}, {"lim_alpha",10ul}, {"eps_svd",1.e-7},
    {"Dincr_abs", 4ul}, {"Dincr_per", 2ul}, {"Dincr_rel", 1.1},
    {"min_Nsv",0ul}, {"max_Nrich",-1},
    {"max_halfsweeps",40ul}, {"min_halfsweeps",1ul},
    {"Dinit",10ul}, {"Qinit",2ul}, {"Dlimit",1000ul},
    {"tol_eigval",1.e-5}, {"tol_state",1.e-5},
    {"savePeriod",0ul}, {"CALC_S_ON_EXIT", true}, {"CONVTEST", DMRG::CONVTEST::VAR_2SITE}
};
 
SpinlessFermions::
SpinlessFermions (const size_t &L, const vector<Param> &params)
:Mpo<Symmetry> (L, Symmetry::qvacuum(), "", PROP::HERMITIAN, PROP::NON_UNITARY, PROP::HAMILTONIAN),
 SpinlessFermionsObservables(L,params,SpinlessFermions::defaults),
 ParamReturner(SpinlessFermions::sweep_defaults)
{
    ParamHandler P(params,SpinlessFermions::defaults);
    size_t Lcell = P.size();
    
    for (size_t l=0; l<N_sites; ++l)
    {
        N_phys += P.get<size_t>("Ly",l%Lcell);
        setLocBasis(F[l].get_basis(),l);
    }
    
    HamiltonianTermsXd<Symmetry> Terms(N_sites, P.get<bool>("OPEN_BC"));
    SpinlessFermionsU1::set_operators(F,P,Terms);
    SpinlessFermionsZ2::add_operators(F,P,Terms);
    Terms.set_name("SpinlessFermions");
    
    this->construct_from_Terms(Terms, Lcell, P.get<bool>("CALC_SQUARE"), P.get<bool>("OPEN_BC"));
    this->precalc_TwoSiteData();
}
 
} // end namespace VMPS
 
#endif