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1;
% calculate total decay for particular level taking in account all branches
function ret=decay_total(g_decay,i)
ret=0;
for k=1:size(g_decay)(1)
ret=ret+g_decay(i,k);
endfor
endfunction
% kroneker delta symbol
function ret=kron_delta(i,j)
if ((i==j))
ret=1;
else
ret=0;
endif
endfunction
% this function create from Liouville density vector
% the density matrix with given modulation frequency
function rho=rhoOfFreq(rhoLiouville, freqIndex, Nlevels, Nfreq)
rho=zeros(Nlevels);
for r=1:Nlevels
for c=1:Nlevels
rho(r,c)=rhoLiouville((freqIndex-1)*Nlevels^2+(r-1)*Nlevels+c);
endfor
endfor
endfunction
% we unwrap density matrix to Liouville density vector and assign all possible
% modulation frequencies as well
% resulting vector should be Nlevels x Nlevels x length(modulation_freq)
function [N, rhoLiouville_w, rhoLiouville_r, rhoLiouville_c]=unfold_density_matrix(Nlevels,Nfreq)
N=Nfreq*Nlevels*Nlevels;
rhoLiouville_w=zeros(N,1);
rhoLiouville_r=zeros(N,1);
rhoLiouville_c=zeros(N,1);
i=0;
for w=1:Nfreq;
for r=1:Nlevels
for c=1:Nlevels
i+=1;
rhoLiouville(i)=0;
rhoLiouville_w(i)=w; % hold frequency modulation index
rhoLiouville_r(i)=r; % hold row value of rho_rc
rhoLiouville_c(i)=c; % hold column value of rho_rc
endfor
endfor
endfor
endfunction
% Liouville operator matrix construction
function L=Liouville_operator_matrix(
N,
H0, g_decay, g_dephasing, dipole_elements,
E_field,
modulation_freq, rhoLiouville_w, rhoLiouville_r, rhoLiouville_c
)
%-------------------------
useful_constants;
L=zeros(N); % NxN matrix
Nfreq=length(modulation_freq);
for p=1:N
for s=1:N
j=rhoLiouville_r(p);
k=rhoLiouville_c(p);
m=rhoLiouville_r(s);
n=rhoLiouville_c(s);
% we garanted to know frequency of final and initial rhoLiouville
w1i=rhoLiouville_w(p);
w2i=rhoLiouville_w(s);
w_jk=modulation_freq(w1i);
w_mn=modulation_freq(w2i);
% thus we know L matrix element frequency which we need to match
w_l=w_jk-w_mn;
% lets search this wrequency in the list of available frequencyes
% but since we not garanteed to find it lets assign temporary 0 to Liouville matrix element
L(p,s)=0;
decay_part=0;
Lt=0;
for w3i=1:Nfreq
w_iner=modulation_freq(w3i);
decay_part=0;
if ((w_iner == w_l))
%such frequency exist in the list of modulation frequencies
if ((w_iner == 0))
% calculate unperturbed part (Hamiltonian without EM field)
L0=H0(j,m)*kron_delta(k,n)-H0(n,k)*kron_delta(j,m);
decay_part=\
( decay_total(g_decay,k)/2 + decay_total(g_decay,j)/2 + g_dephasing(j,k) )* kron_delta(j,m)*kron_delta(k,n) \
- kron_delta(m,n)*kron_delta(j,k)*g_decay(m,j) ;
Lt=L0;
else
% calculate perturbed part (Hamiltonian with EM field)
% in othe word interactive part of Hamiltonian
Li= ( dipole_elements(j,m)*kron_delta(k,n)-dipole_elements(n,k)*kron_delta(j,m) )*E_field(w3i);
Lt=Li;
endif
%Lt=-im_one/hbar*Lt*kron_delta(w_jk-w_iner,w_mn); % above if should be done only if kron_delta is not zero
% no need for above kron_delta since the same conditon checked in the outer if statement
Lt=-im_one/hbar*Lt - decay_part;
endif
endfor
if ((p == s))
Lt+=-im_one*w_jk;
endif
L(p,s)=Lt;
endfor
endfor
endfunction
% now generally rhoL_dot=0=L*rhoL has infinite number of solutions
% since we always can resclale rho vector with arbitrary constant
% lets constrain our density matrix with some physical meaning
% sum(rho_ii)=1 (sum of all populations (with zero modulation frequency) scales to 1
% we will replace first row of Liouville operator with this condition
% thus rhoLiouville_dot(1)=1
function [rhoLiouville_dot, L]=constran_rho_and_match_L(
N, L,
modulation_freq, rhoLiouville_w, rhoLiouville_r, rhoLiouville_c)
for i=1:N
w2i=rhoLiouville_w(i);
m=rhoLiouville_r(i);
n=rhoLiouville_c(i);
w=modulation_freq(w2i);
if ((w==0) & (m==n))
L(1,i)=1;
else
L(1,i)=0;
endif
endfor
rhoLiouville_dot= zeros(N,1);
% sum(rho_ii)=1 (sum of all populations (with zero modulation frequency) scales to 1
% we will replace first row of Liouville operator with this condition
% thus rhoLiouville_dot(1)=1
rhoLiouville_dot(1)=1;
endfunction
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