CalcSpectrumByFullDiag.cpp File Reference

Functions to perform spectrum calculations with the full-diagonalization method. More...

#include <complex>
#include "global.hpp"
#include <ctime>
#include "struct.hpp"
#include "lapack_diag.hpp"
#include "mltply.hpp"
#include "mltplyCommon.hpp"
#include "CalcTime.hpp"
#include "common/setmemory.hpp"
#include "CalcSpectrum.hpp"

Go to the source code of this file.

Functions
int	CalcSpectrumByFullDiag (struct EDMainCalStruct *X, int Nomega, int NdcSpectrum, std::complex< double > **dcSpectrum, std::complex< double > *dcomega, std::complex< double > **v1Org)
	Compute the Green function with the Lehmann representation and FD \[ G(z) = \sum_n \frac{|\langle n|c|0\rangle|^2}{z - E_n} \] . More...

Detailed Description

Functions to perform spectrum calculations with the full-diagonalization method.

Definition in file CalcSpectrumByFullDiag.cpp.

Function Documentation

CalcSpectrumByFullDiag()

int CalcSpectrumByFullDiag	(	struct EDMainCalStruct *	X,
		int	Nomega,
		int	NdcSpectrum,
		std::complex< double > **	dcSpectrum,
		std::complex< double > *	dcomega,
		std::complex< double > **	v1Org
	)

Compute the Green function with the Lehmann representation and FD

\[ G(z) = \sum_n \frac{|\langle n|c|0\rangle|^2}{z - E_n} \]

.

Author

Mitsuaki Kawamura (The University of Tokyo)

• Generate fully stored Hamiltonian. Because v0 & v1 are overwritten, copy v0 into ::vg.

• v0 becomes eigenvalues in lapack_diag(), and v1 becomes eigenvectors

• Compute \(|\langle n|c|0\rangle|^2\) for all \(n\) and store them into v1, where \(c|0\rangle\) is ::vg.

• Compute spectrum

  \[ \sum_n \frac{|\langle n|c|0\rangle|^2}{z - E_n} \]

Parameters

[in,out]	X
[in]	Nomega	Number of frequencies
[out]	dcSpectrum	[Nomega] Spectrum
[in]	dcomega	[Nomega] Frequency

Definition at line 37 of file CalcSpectrumByFullDiag.cpp.

References EDMainCalStruct::Bind, BindStruct::Check, PhysList::energy, GetExcitedState(), CheckList::idim_max, lapack_diag(), mltply(), BindStruct::Phys, StartTimer(), StopTimer(), v0, v1, and zclear().

Referenced by CalcSpectrum().

{
  int idim, jdim, iomega, idim_max_int, idcSpectrum;
  std::complex<double> **vR, **vL, vRv, vLv, *vLvvRv;
  idim_max_int = (int)X->Bind.Check.idim_max;
  vR = cd_2d_allocate(idim_max_int, 1);
  vL = cd_2d_allocate(idim_max_int, 1);
  vLvvRv = cd_1d_allocate(idim_max_int);

  StartTimer(6301);
  zclear((X->Bind.Check.idim_max + 1)*(X->Bind.Check.idim_max + 1), &v0[0][0]);
  zclear((X->Bind.Check.idim_max + 1)*(X->Bind.Check.idim_max + 1), &v1[0][0]);
  for (idim = 1; idim <= X->Bind.Check.idim_max; idim++) v1[idim][idim] = 1.0;
  mltply(&(X->Bind), X->Bind.Check.idim_max, v0, v1);
  StopTimer(6301);
  StartTimer(6302);
  lapack_diag(&(X->Bind));
  StopTimer(6302);
  zclear(X->Bind.Check.idim_max, &vR[1][0]);
  GetExcitedState(&(X->Bind), 1, vR, v1Org, 0);
  for (idcSpectrum = 0; idcSpectrum < NdcSpectrum; idcSpectrum++) {
    StartTimer(6303);
    zclear(X->Bind.Check.idim_max, &vL[1][0]);
    GetExcitedState(&(X->Bind), 1, vL, v1Org, idcSpectrum + 1);
    for (idim = 0; idim < idim_max_int; idim++) {
      vRv = 0.0;
      vLv = 0.0;
      for (jdim = 0; jdim < idim_max_int; jdim++) {
        vRv += conj(v1[jdim][idim]) * vR[jdim][1];
        vLv += conj(v1[jdim][idim]) * vL[jdim][1];
      }
      vLvvRv[idim] = conj(vLv) * vRv;
    }/*for (idim = 0; idim < idim_max_int; idim++)*/
    StopTimer(6303);
    StartTimer(6304);
    for (iomega = 0; iomega < Nomega; iomega++) {
      dcSpectrum[iomega][idcSpectrum] = 0.0;
      for (idim = 0; idim < idim_max_int; idim++) {
        dcSpectrum[iomega][idcSpectrum] += vLvvRv[idim] / (dcomega[iomega] - X->Bind.Phys.energy[idim]);
      }/*for (idim = 0; idim < idim_max_int; idim++)*/
    }/*for (iomega = 0; iomega < Nomega; iomega++)*/
    StopTimer(6304);
  }/*for (idcSpectrum = 1; idcSpectrum < NdcSpectrum; idcSpectrum++)*/
  free_cd_2d_allocate(vL);
  free_cd_2d_allocate(vR);
  free_cd_1d_allocate(vLvvRv);
  return TRUE;
}/*CalcSpectrumByFullDiag*/