HubbardU1.h

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#ifndef STRAWBERRY_HUBBARDMODEL_U1CHARGEONLY
#define STRAWBERRY_HUBBARDMODEL_U1CHARGEONLY
 
//include "bases/FermionBase.h"
//include "symmetry/S1xS2.h"
//include "Mpo.h"
//include "ParamHandler.h" // from HELPERS
//include "models/HubbardObservables.h"
#include "models/HubbardU1xU1.h"
 
namespace VMPS
{
 
class HubbardU1 : public Mpo<Sym::U1<Sym::ChargeU1>,double>, public HubbardObservables<Sym::U1<Sym::ChargeU1> >, public ParamReturner
{
public:
    
    typedef Sym::U1<Sym::ChargeU1> Symmetry;
    MAKE_TYPEDEFS(HubbardU1)
    
    
    HubbardU1() : Mpo(){};
    
    HubbardU1(Mpo<Symmetry> &Mpo_input, const vector<Param> &params)
    :Mpo<Symmetry>(Mpo_input),
     HubbardObservables(this->N_sites,params,HubbardU1::defaults),
     ParamReturner()
    {
        ParamHandler P(params,HubbardU1::defaults);
        size_t Lcell = P.size();
        N_phys = 0;
        for (size_t l=0; l<N_sites; ++l) N_phys += P.get<size_t>("Ly",l%Lcell);
        this->precalc_TwoSiteData();
        this->HERMITIAN = true;
        this->HAMILTONIAN = true;
    };
    
    HubbardU1 (const size_t &L, const vector<Param> &params, const BC &boundary=BC::OPEN, const DMRG::VERBOSITY::OPTION &VERB=DMRG::VERBOSITY::OPTION::ON_EXIT);
    
    static qarray<1> singlet (int N) {return qarray<1>{N};};
    static constexpr MODEL_FAMILY FAMILY = HUBBARD;
    static constexpr int spinfac = 2;
    
    static const std::map<string,std::any> defaults;
};
 
const std::map<string,std::any> HubbardU1::defaults = 
{
    {"t",1.}, {"tPrime",0.}, {"tRung",1.}, 
    {"mu",0.}, {"t0",0.}, 
    {"U",0.}, {"Uph",0.},
    {"V",0.}, {"Vrung",0.}, 
    {"Vxy",0.}, {"Vz",0.},
    {"Bz",0.}, {"Bx",0.}, 
    {"J",0.}, {"Jperp",0.}, {"J3site",0.},
    {"X",0.}, {"Xperp",0.},
    {"REMOVE_DOUBLE",false}, {"REMOVE_EMPTY",false}, {"REMOVE_UP",false}, {"REMOVE_DN",false}, {"mfactor",1}, {"k",0},
    {"maxPower",2ul}, {"CYLINDER",false}, {"Ly",1ul}
};
 
HubbardU1::
HubbardU1 (const size_t &L, const vector<Param> &params, const BC &boundary, const DMRG::VERBOSITY::OPTION &VERB)
:Mpo<Symmetry> (L, Symmetry::qvacuum(), "", PROP::HERMITIAN, PROP::NON_UNITARY, boundary, VERB),
 HubbardObservables(L,params,HubbardU1::defaults),
 ParamReturner()
{
    ParamHandler P(params,HubbardU1::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().qloc(),l);
    }
    
    param1d U = P.fill_array1d<double>("U", "Uorb", F[0].orbitals(), 0);
    if (isfinite(U.a.sum()))
    {
        this->set_name("Hubbard");
    }
    else if (P.HAS_ANY_OF({"J", "J3site"}))
    {
        this->set_name("t-J");
    }
    else
    {
        this->set_name("U=∞-Hubbard");
    }
    
    PushType<SiteOperator<Symmetry,double>,double> pushlist;
    std::vector<std::vector<std::string>> labellist;
    HubbardU1xU1::set_operators(F, P, pushlist, labellist, boundary);
    
    this->construct_from_pushlist(pushlist, labellist, Lcell);
    this->finalize(PROP::COMPRESS, P.get<size_t>("maxPower"));
    
    this->precalc_TwoSiteData();
}
 
} // end namespace VMPS::models
 
#endif