% some physical constants hbar=1; im_one=0+1i; %three_levels; two_levels; Nfreq=length(modulation_freq); % now we create Liouville indexes list % we unwrap density matrix and assign all posible % frequencies as well % resulting vector should be Nlevels x Nlevels x length(modulation_freq) N=length(modulation_freq)*Nlevels*Nlevels; rhoLiouville=zeros(N,1); rhoLiouville_w=rhoLiouville; rhoLiouville_r=rhoLiouville; rhoLiouville_c=rhoLiouville; i=0; for w=1:length(modulation_freq) for r=1:Nlevels for c=1:Nlevels i+=1; rhoLiouville(i)=0; rhoLiouville_w(i)=w; rhoLiouville_r(i)=r; rhoLiouville_c(i)=c; endfor endfor endfor % Liouville operator matrix L=zeros(N); % NxN matrix Li=zeros(N); % NxN Liouville interactive L0=zeros(N); % NxN Liouville from unperturbed hamiltonian function ret=decay_total(g_decay,i) ret=0; for k=1:size(g_decay)(1) ret=ret+g_decay(i,k); endfor endfunction function ret=kron_delta(i,j) if ((i==j)) ret=1; else ret=0; endif endfunction 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)) 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 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 % 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 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=rhoLiouville*0; % 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; %solving for density matrix vector rhoLiouville=L\rhoLiouville_dot; % 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 rho_0=rhoOfFreq(rhoLiouville, 1, Nlevels, Nfreq) rho_1=rhoOfFreq(rhoLiouville, 2, Nlevels, Nfreq) rho_2=rhoOfFreq(rhoLiouville, 3, Nlevels, Nfreq) %rho_l=rhoOfFreq(rhoLiouville, Nfreq, Nlevels, Nfreq) %L*rhoLiouville