SpinSiteSU2.h

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#ifndef SPINSITESU2_H_
#define SPINSITESU2_H_
 
#include "symmetry/kind_dummies.h"
 
#include "DmrgTypedefs.h"
 
#include "symmetry/S1xS2.h"
#include "symmetry/SU2.h"
#include "symmetry/U1.h"
 
#include "tensors/SiteOperatorQ.h"
 
template <typename Symmetry, size_t order> class SpinSite;
 
template <>
class SpinSite<Sym::SU2<Sym::SpinSU2>,0ul>
{
    typedef double Scalar;
    typedef Sym::SU2<Sym::SpinSU2> Symmetry;
    typedef SiteOperatorQ<Symmetry,Eigen::Matrix<Scalar,Eigen::Dynamic,Eigen::Dynamic> > OperatorType;
public:
    SpinSite() {};
    SpinSite(std::size_t D_input, int mfactor_input=1);
    
    OperatorType Id_1s() const {return Id_1s_;}
    
    OperatorType S_1s() const {return S_1s_;}
 
    OperatorType Q_1s() const {return Q_1s_;}
 
    Qbasis<Symmetry> basis_1s() const {return basis_1s_;}
protected:
    std::size_t D;
    
    Qbasis<Symmetry> basis_1s_;
 
    OperatorType Id_1s_; //identity
    OperatorType S_1s_; //spin
    OperatorType Sdag_1s_; //spin
    OperatorType Q_1s_; //quadrupole moment
};
 
SpinSite<Sym::SU2<Sym::SpinSU2>,0ul>::
SpinSite(std::size_t D_input, int mfactor_input)
:D(D_input)
{
    //create basis for one Spin Site
    typename Symmetry::qType Q = {static_cast<int>(D)};
    Eigen::Index inner_dim = 1;
    std::vector<std::string> ident;
    ident.push_back("spin");
    
    basis_1s_.push_back(Q,inner_dim,ident);
    
    Id_1s_ = OperatorType({1},basis_1s_,"id");
    S_1s_ = OperatorType({3},basis_1s_,"S");
 
    Scalar locS = 0.5*static_cast<double>(D-1);
    S_1s_( "spin", "spin" ) = std::sqrt(locS*(locS+1.));
    Sdag_1s_ = S_1s_.adjoint();
    Q_1s_ = std::sqrt(2.)*OperatorType::prod(S_1s_,S_1s_,{5});
    Id_1s_.setIdentity();
}
 
#endif //SPINSITESU2_H_