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author | Eugeniy Mikhailov <evgmik@gmail.com> | 2009-12-09 21:11:00 +0000 |
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committer | Eugeniy Mikhailov <evgmik@gmail.com> | 2009-12-09 21:11:00 +0000 |
commit | 50af7e38454d34b4932140449669393b9b9582ec (patch) | |
tree | cf274798a8bf77979eac3cefafd13e42bd72fb57 /useful_functions.m | |
parent | 40dafe1f7e7194103476277083521c95c38ccefc (diff) | |
download | multi_mode_eit-50af7e38454d34b4932140449669393b9b9582ec.tar.gz multi_mode_eit-50af7e38454d34b4932140449669393b9b9582ec.zip |
extra work moved to function, code for sweeping laser is added
Diffstat (limited to 'useful_functions.m')
-rw-r--r-- | useful_functions.m | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/useful_functions.m b/useful_functions.m index 748a677..5522afb 100644 --- a/useful_functions.m +++ b/useful_functions.m @@ -28,3 +28,116 @@ function rho=rhoOfFreq(rhoLiouville, freqIndex, Nlevels, Nfreq) 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 + |