R2917/HeisEn.cpp
38aa3c940a24master

HeisEn.cpp
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			#include "HeisEn.h"
			#include "SpinOp.h"
			#include "Stepper.h"
			#include "Amplitude.h"
			#include "SpinState.h"
			#include "linalg.h"
			#include "Jastrow.h"

			void HeisEn::measure()
			{
			const Amplitude* amp=m_stepper->GetAmp();
			Quantity::measure();
			const SpinState* st=amp->GetSpinState();
			BigComplex out(0);
			int taus[16]={1,0,-1,0,0,1,0,-1,1,1,-1,-1,1,-1,-1,1};
			double Js[8]={1,1,1,1,m_jr,m_jr,m_jr,m_jr};
			size_t nm=4;
			if(m_jr!=0) nm=8;
			for(size_t x=0;x<st->GetL();++x){
			for(size_t y=0;y<st->GetL();++y){
			for(size_t t=0;t<nm;++t){
			size_t jx=linalg::mod(int(x)+taus[2*t],st->GetL());
			size_t jy=linalg::mod(int(y)+taus[2*t+1],st->GetL());
			out+=Js[t]SpinOp::SizSjz(amp,x,y,jx,jy)+0.5(SpinOp::SipSjm(amp,x,y,jx,jy)+SpinOp::SimSjp(amp,x,y,jx,jy));
			}
			}
			}
			out*=conj(amp->Amp());
			if(st->GetJas())
			out*=st->GetJas()->Jas();
			BigDouble w=m_stepper->weight();
			m_vals+=std::complex<double>(0.5out/double(st->GetL()st->GetL())/w);
			}