diff options
-rw-r--r-- | psr/basis_transformation.m | 57 | ||||
-rw-r--r-- | psr/dipole_elementRb87D1line.m | 177 | ||||
-rw-r--r-- | psr/field_description.m | 14 | ||||
-rw-r--r-- | psr/output_results.m | 31 | ||||
-rw-r--r-- | psr/output_xi_results.m | 46 | ||||
-rw-r--r-- | psr/psr.m | 149 | ||||
-rw-r--r-- | psr/rb87_D1_line.m | 150 | ||||
-rw-r--r-- | psr/useful_constants.m | 6 | ||||
-rw-r--r-- | psr/useful_functions.m | 337 |
9 files changed, 967 insertions, 0 deletions
diff --git a/psr/basis_transformation.m b/psr/basis_transformation.m new file mode 100644 index 0000000..82945fe --- /dev/null +++ b/psr/basis_transformation.m @@ -0,0 +1,57 @@ +1; + +% matrix of circular to linear transformation +% [x, y, z]' = lin2circ * [r, l, z]' +function transformation_matrix = circ2lin() + transformation_matrix = ... + [ ... + [ 1/sqrt(2), 1/sqrt(2), 0]; ... + [-1i/sqrt(2), 1i/sqrt(2), 0]; ... + [ 0, 0, 1] ... + ]; +endfunction + + +% matrix of linear to circular transformation +% [r, l, z]' = lin2circ * [x, y, z]' +function transformation_matrix = lin2circ() + transformation_matrix = ... + [ ... + [ 1/sqrt(2), 1i/sqrt(2), 0]; ... + [ 1/sqrt(2), -1i/sqrt(2), 0]; ... + [ 0, 0, 1] ... + ]; +endfunction +% linear basis rotation +% x axis untouched +% z and y rotated by angle theta around 'x' axis +% [x_new, y_new, z_new]' = oldlin2newlin * [x_old, y_old, z_old]' +function oldlin2newlin_m = oldlin2newlin(theta) + oldlin2newlin_m = [ ... + [ 1, 0, 0]; ... + [ 0, cos(theta), -sin(theta)]; ... + [ 0, sin(theta), cos(theta)]... + ]; +endfunction + +% rotate x polarized light by angle phi around +% light propagation axis (Z) +function [E_field_x, E_field_y] = rotXpolarization(phi, E_field_linear) + % important negative frequency behave as they rotate in opposite direction + E_field_x=cos(phi)*E_field_linear; + E_field_y=sin(phi)*E_field_linear; +endfunction + +% transform x,y,z linearly polarized light in the lab/light system coordinate +% to left, right, linear along z atom system of coordinate +% atom magnetic field is along new axis Z wich is at angle theta with respect to +% light propagation direction +function E_field_pos_freq=xyz_lin2atomic_axis_polarization(theta, E_field_lab_pos_freq) + coord_transf_m = lin2circ() * oldlin2newlin(theta); + E_field_pos_freq.right = coord_transf_m(1,1)*E_field_lab_pos_freq.x + coord_transf_m(1,2)*E_field_lab_pos_freq.y + coord_transf_m(1,3)*E_field_lab_pos_freq.z; + E_field_pos_freq.left = coord_transf_m(2,1)*E_field_lab_pos_freq.x + coord_transf_m(2,2)*E_field_lab_pos_freq.y + coord_transf_m(2,3)*E_field_lab_pos_freq.z; + E_field_pos_freq.linear = coord_transf_m(3,1)*E_field_lab_pos_freq.x + coord_transf_m(3,2)*E_field_lab_pos_freq.y + coord_transf_m(3,3)*E_field_lab_pos_freq.z; +endfunction + + +% vim: ts=2:sw=2:fdm=indent diff --git a/psr/dipole_elementRb87D1line.m b/psr/dipole_elementRb87D1line.m new file mode 100644 index 0000000..9235274 --- /dev/null +++ b/psr/dipole_elementRb87D1line.m @@ -0,0 +1,177 @@ +function d=dipole_elementRb87D1line(Fl,ml,Fu,mu) +% Fl, ml are F and m quantum numbers of lower state +% Fu, mu are F and m quantum numbers of upper state +% F is total momentum and m is projection + d.left = 0; %default return value + d.linear = 0; %default return value + d.right = 0; %default return value + if ( mu==(ml+1) ) + % sigma plus polarization + % ------ Fl=2 -> Fu=2 -------- + if ( (ml==-2) & (Fl==2) & (Fu==2) ) + d.right=sqrt(1/6); + endif + if ( (ml==-1) & (Fl==2) & (Fu==2) ) + d.right=sqrt(1/4); + endif + if ( (ml== 0) & (Fl==2) & (Fu==2) ) + d.right=sqrt(1/4); + endif + if ( (ml== 1) & (Fl==2) & (Fu==2) ) + d.right=sqrt(1/6); + endif + if ( (ml== 2) & (Fl==2) & (Fu==2) ) + d.right=0; + endif + % ------ Fl=2 -> Fu=1 -------- + if ( (ml==-2) & (Fl==2) & (Fu==1) ) + d.right=sqrt(1/2); + endif + if ( (ml==-1) & (Fl==2) & (Fu==1) ) + d.right=sqrt(1/4); + endif + if ( (ml== 0) & (Fl==2) & (Fu==1) ) + d.right=sqrt(1/12); + endif + if ( (ml== 1) & (Fl==2) & (Fu==1) ) + d.right=0; + endif + if ( (ml== 2) & (Fl==2) & (Fu==1) ) + d.right=0; + endif + % ------ Fl=1 -> Fu=2 -------- + if ( (ml==-1) & (Fl==1) & (Fu==2) ) + d.right = -sqrt(1/12); + endif + if ( (ml== 0) & (Fl==1) & (Fu==2) ) + d.right = -sqrt(1/4); + endif + if ( (ml== 1) & (Fl==1) & (Fu==2) ) + d.right = -sqrt(1/2); + endif + % ------ Fl=1 -> Fu=1 -------- + if ( (ml==-1) & (Fl==1) & (Fu==1) ) + d.right = -sqrt(1/12); + endif + if ( (ml== 0) & (Fl==1) & (Fu==1) ) + d.right = -sqrt(1/12); + endif + if ( (ml== 1) & (Fl==1) & (Fu==1) ) + d.right = 0; + endif + endif + if ( mu==(ml+0) ) + % pi polarization + % ------ Fl=2 -> Fu=2 -------- + if ( (ml==-2) & (Fl==2) & (Fu==2) ) + d.linear=-sqrt(1/3); + endif + if ( (ml==-1) & (Fl==2) & (Fu==2) ) + d.linear=-sqrt(1/12); + endif + if ( (ml== 0) & (Fl==2) & (Fu==2) ) + d.linear=0; + endif + if ( (ml== 1) & (Fl==2) & (Fu==2) ) + d.linear=sqrt(1/12); + endif + if ( (ml== 2) & (Fl==2) & (Fu==2) ) + d.linear=sqrt(1/3); + endif + % ------ Fl=2 -> Fu=1 -------- + if ( (ml==-2) & (Fl==2) & (Fu==1) ) + d.linear = 0; + endif + if ( (ml==-1) & (Fl==2) & (Fu==1) ) + d.linear=sqrt(1/4); + endif + if ( (ml== 0) & (Fl==2) & (Fu==1) ) + d.linear=sqrt(1/3); + endif + if ( (ml== 1) & (Fl==2) & (Fu==1) ) + d.linear=sqrt(1/4); + endif + if ( (ml== 2) & (Fl==2) & (Fu==1) ) + d.linear = 0; + endif + % ------ Fl=1 -> Fu=2 -------- + if ( (ml==-1) & (Fl==1) & (Fu==2) ) + d.linear = sqrt(1/4); + endif + if ( (ml== 0) & (Fl==1) & (Fu==2) ) + d.linear = sqrt(1/2); + endif + if ( (ml== 1) & (Fl==1) & (Fu==2) ) + d.linear = sqrt(1/4); + endif + % ------ Fl=1 -> Fu=1 -------- + if ( (ml==-1) & (Fl==1) & (Fu==1) ) + d.linear = sqrt(1/12); + endif + if ( (ml== 0) & (Fl==1) & (Fu==1) ) + d.linear = 0; + endif + if ( (ml== 1) & (Fl==1) & (Fu==1) ) + d.linear = -sqrt(1/12); + endif + endif + if ( mu==(ml-1) ) + % sigma minus polarization + % ------ Fl=2 -> Fu=2 -------- + if ( (ml==-2) & (Fl==2) & (Fu==2) ) + d.left = 0; + endif + if ( (ml==-1) & (Fl==2) & (Fu==2) ) + d.left = -sqrt(1/6); + endif + if ( (ml== 0) & (Fl==2) & (Fu==2) ) + d.left = -sqrt(1/4); + endif + if ( (ml== 1) & (Fl==2) & (Fu==2) ) + d.left = -sqrt(1/4); + endif + if ( (ml== 2) & (Fl==2) & (Fu==2) ) + d.left = -sqrt(1/6); + endif + % ------ Fl=2 -> Fu=1 -------- + if ( (ml==-2) & (Fl==2) & (Fu==1) ) + d.left = 0; + endif + if ( (ml==-1) & (Fl==2) & (Fu==1) ) + d.left = 0; + endif + if ( (ml== 0) & (Fl==2) & (Fu==1) ) + d.left = sqrt(1/12); + endif + if ( (ml== 1) & (Fl==2) & (Fu==1) ) + d.left = sqrt(1/4); + endif + if ( (ml== 2) & (Fl==2) & (Fu==1) ) + d.left = sqrt(1/2); + endif + % ------ Fl=1 -> Fu=2 -------- + if ( (ml==-1) & (Fl==1) & (Fu==2) ) + d.left = -sqrt(1/2); + endif + if ( (ml== 0) & (Fl==1) & (Fu==2) ) + d.left = -sqrt(1/4); + endif + if ( (ml== 1) & (Fl==1) & (Fu==2) ) + d.left = -sqrt(1/12); + endif + % ------ Fl=1 -> Fu=1 -------- + if ( (ml==-1) & (Fl==1) & (Fu==1) ) + d.left = 0; + endif + if ( (ml== 0) & (Fl==1) & (Fu==1) ) + d.left = sqrt(1/12); + endif + if ( (ml== 1) & (Fl==1) & (Fu==1) ) + d.left = sqrt(1/12); + endif + endif +endfunction + + + +% vim: ts=2:sw=2:fdm=indent diff --git a/psr/field_description.m b/psr/field_description.m new file mode 100644 index 0000000..738ebe3 --- /dev/null +++ b/psr/field_description.m @@ -0,0 +1,14 @@ +1; + +%EM field definition +Ed=10.12; %drive +Edc=conj(Ed); +Ep=0.8*Ed; %probe +Epc=conj(Ep); +Em=-Ep; % opposite sideband (resulting from EOM modulation of drive) +Emc=conj(Em); +%wd=w13; +%wp=w12; +%wm=wd-(wp-wd); +%light_positive_freq = [wp, wd, wp-wd]; +E_field = [Ep, Ed, 0 ]; diff --git a/psr/output_results.m b/psr/output_results.m new file mode 100644 index 0000000..eca6085 --- /dev/null +++ b/psr/output_results.m @@ -0,0 +1,31 @@ +1; + + +load '/tmp/relative_transmission_vs_detuning.mat' ; + +figure(1); +hold off; +zoom_factor=1; +plot(detuning_freq, zoom_factor*(relative_transmission_vs_detuning), '-'); +title("relative transmission"); +xlabel("two photon detuning"); + +%load 'xi_vs_detuning.mat' ; + +%figure(1); + %hold off; + %plot(detuning_freq, imag(xi_linear), '-1;linear;'); + %hold on; + %plot(detuning_freq, imag(xi_left), '-2;left;'); + %plot(detuning_freq, imag(xi_right), '-3;right;'); + %title("probe absorption"); + %hold off; +%figure(2); + %hold off; + %plot(detuning_freq, real(xi_linear), '-1;linear;'); + %hold on; + %plot(detuning_freq, real(xi_left), '-2;left;'); + %plot(detuning_freq, real(xi_right), '-3;right;'); + %title("probe dispersion"); + %hold off; + diff --git a/psr/output_xi_results.m b/psr/output_xi_results.m new file mode 100644 index 0000000..7dc3855 --- /dev/null +++ b/psr/output_xi_results.m @@ -0,0 +1,46 @@ +1; + + +load '/tmp/xi_vs_detuning.mat' ; + +figure(1); +hold off; +plot(detuning_freq, real(xi_left-xi_right), '-'); +title("differential real xi"); +xlabel("two photon detuning"); + +figure(2); +hold off; +plot(detuning_freq, imag(xi_left-xi_right), '-'); +title("differential imag xi"); +xlabel("two photon detuning"); + +figure(3); +hold off; +plot(detuning_freq, imag(xi_left), '-', detuning_freq, imag(xi_right), '-'); +title("imag xi"); +xlabel("two photon detuning"); + +figure(4); +hold off; +plot(detuning_freq, real(xi_left), '-', detuning_freq, real(xi_right), '-'); +title("real xi"); +xlabel("two photon detuning"); + +%figure(1); + %hold off; + %plot(detuning_freq, imag(xi_linear), '-1;linear;'); + %hold on; + %plot(detuning_freq, imag(xi_left), '-2;left;'); + %plot(detuning_freq, imag(xi_right), '-3;right;'); + %title("probe absorption"); + %hold off; +%figure(2); + %hold off; + %plot(detuning_freq, real(xi_linear), '-1;linear;'); + %hold on; + %plot(detuning_freq, real(xi_left), '-2;left;'); + %plot(detuning_freq, real(xi_right), '-3;right;'); + %title("probe dispersion"); + %hold off; + diff --git a/psr/psr.m b/psr/psr.m new file mode 100644 index 0000000..7c8f604 --- /dev/null +++ b/psr/psr.m @@ -0,0 +1,149 @@ +1; +clear all; +t0 = clock (); % we will use this latter to calculate elapsed time + + +% load useful functions; +useful_functions; + +% some physical constants +useful_constants; + +basis_transformation; % load subroutines + +% load atom energy levels and decay description +rb87_D1_line; +%four_levels_with_polarization; +%four_levels; +%three_levels; +%two_levels; + +% load EM field description +field_description; + +%Nfreq=length(modulation_freq); + + + +%tune probe frequency +detuning_p=0; +N_detun_steps=100; +%detuning_p_min=-B_field*gmg*4; % span +/-4 Zeeman splitting +detuning_p_min=-10040.0; +detuning_p_max=-detuning_p_min; +detuning_freq=zeros(1,N_detun_steps+1); +kappa_p =zeros(1,N_detun_steps+1); +kappa_m =zeros(1,N_detun_steps+1); +detun_step=(detuning_p_max-detuning_p_min)/N_detun_steps; + +fprintf (stderr, "calculating atom properties\n"); +fflush (stderr); +pfile='rb87_D1_line.m'; % the parent file from which L0_and_polarization_submatrices calculated +cfile='L0m_and_polarizability_calculated.mat'; % the child file to which calculated matrices writen +[s, err, msg] = stat (pfile); +if(err) + %file does not exist + disp('Big troubles are coming, no file to define Hamiltonian)'); + msg=cstrcat('File: ', pfile, ' is missing...exiting'); + disp(msg); + return; +else + pfile_mtime=s.mtime; +endif +[s, err, msg] = stat (cfile); +if(err) + %file does not exist + cfile_mtime=0; +else + cfile_mtime=s.mtime; +endif; +if ( cfile_mtime >= pfile_mtime) + % matrices already calculated and up to date, all we need to load them + load(cfile); + else + % calculate E_field independent properties of the atom + % to be used as sub matrix templates for Liouville operator matrix + [L0m, polarizability_m]=L0_and_polarization_submatrices( ... + Nlevels, ... + H0, g_decay, g_dephasing, dipole_elements ... + ); + save(cfile, 'L0m', 'polarizability_m'); + endif +elapsed_time = etime (clock (), t0); +fprintf (stderr, "elapsed time so far is %.3f sec\n",elapsed_time); +fflush (stderr); + +global atom_properties; +atom_properties.L0m=L0m; +atom_properties.polarizability_m=polarizability_m; +atom_properties.dipole_elements=dipole_elements; + +%light_positive_freq = [wp]; +E_field_drive = [0 ]; +E_field_probe = [Ep ]; +E_field_zero = [0 ]; +E_field_lab_pos_freq.linear = E_field_zero + (1.00000+0.00000i)*E_field_probe + (1.00000+0.00000i)*E_field_drive; +%E_field_lab_pos_freq.right = E_field_zero + (0.00000+0.00000i)*E_field_probe + (0.00000+0.00000i)*E_field_drive; +%E_field_lab_pos_freq.left = E_field_zero + (0.00000+0.00000i)*E_field_probe + (0.00000+0.00000i)*E_field_drive; + +% phi is angle between linear polarization and axis x +phi=pi*2/8; +% theta is angle between lab z axis (light propagation direction) and magnetic field axis (z') +theta=0; +% psi_el is the ellipticity parameter (phase difference between left and right polarization) +psi_el=-3/180*pi; + +% we define light as linearly polarized +% where phi is angle between light polarization and axis x + % only sign of modulation frequency is important now + % we define actual frequency later on + [E_field_lab_pos_freq.x, E_field_lab_pos_freq.y] = rotXpolarization(phi, E_field_lab_pos_freq.linear); + E_field_lab_pos_freq.z=E_field_zero; + + E_field_pos_freq=xyz_lin2atomic_axis_polarization(theta, E_field_lab_pos_freq); + E_field_pos_freq.left*=exp(I*psi_el); + + +fprintf (stderr, "tuning laser in forloop to set conditions vs detuning\n"); +fflush (stderr); +for detuning_p_cntr=1:N_detun_steps+1; + wp0=w_pf1-w_sf2; %Fg=2 -> Fe=1 + %wd=w_pf1-w_hpf_ground; + detuning_p=detuning_p_min+detun_step*(detuning_p_cntr-1); + wp=wp0+detuning_p; + light_positive_freq=[ wp]; + % we calculate dc and negative frequiencies as well as amplitudes + [modulation_freq, E_field] = ... + light_positive_frequencies_and_amplitudes2full_set_of_modulation_frequencies_and_amlitudes(... + light_positive_freq, E_field_pos_freq); + freq_index=freq2index(wp,modulation_freq); + + atom_field_problem.E_field = E_field; + atom_field_problem.modulation_freq = modulation_freq; + atom_field_problem.freq_index = freq_index; + + problems_cell_array{detuning_p_cntr}=atom_field_problem; + + + %kappa_p(detuning_p_cntr)=susceptibility_steady_state_at_freq( atom_field_problem); + detuning_freq(detuning_p_cntr)=detuning_p; +endfor + +save '/tmp/problem_definition.mat' problems_cell_array atom_properties detuning_freq ; +fprintf (stderr, "now really hard calculations begin\n"); +fflush (stderr); +% once we define all problems the main job is done here +%kappa_p=cellfun( @susceptibility_steady_state_at_freq, problems_cell_array); +%kappa_p=parcellfun(2, @susceptibility_steady_state_at_freq, problems_cell_array); +[xi_linear, xi_left, xi_right]=parcellfun(2, @susceptibility_steady_state_at_freq, problems_cell_array); +%relative_transmission_vs_detuning=parcellfun(2, @total_relative_transmission, problems_cell_array); +%relative_transmission_vs_detuning=cellfun(@total_relative_transmission, problems_cell_array); + +save '/tmp/xi_vs_detuning.mat' detuning_freq xi_linear xi_left xi_right ; +%save '/tmp/relative_transmission_vs_detuning.mat' detuning_freq relative_transmission_vs_detuning; + +output_xi_results; + +elapsed_time = etime (clock (), t0) + +% vim: ts=2:sw=2:fdm=indent diff --git a/psr/rb87_D1_line.m b/psr/rb87_D1_line.m new file mode 100644 index 0000000..ecdd6a3 --- /dev/null +++ b/psr/rb87_D1_line.m @@ -0,0 +1,150 @@ +1; +useful_constants; + +% note all frequency values are in MHz + +% 87Rb D1 line +% +% m=-2 m=-1 m=0 m=1 m=2 +% ---- ---- ---- ---- ---- |P,F=2> +% +% ---- ---- ---- |P,F=1> +% m=-1 m=0 m=1 +% +% +% +% +% +% m=-2 m=-1 m=0 m=1 m=2 +% ---- ---- ---- ---- ---- |S,F=2> +% +% ---- ---- ---- |S,F=1> +% m=-1 m=0 m=1 + + +w_hpf_ground=6834; +w_hpf_exited=817; +w_sf2 = w_hpf_ground; % Distance from |S,F=1> to |S,F=2> +w_pf1 =1e9; % something big Distance from |S,F=1> to |P,F=1> +w_pf2 = w_pf1+w_hpf_exited; %Distance from |S,F=1> to |P,F=2> +gmg=.7; % gyro magnetic ration for ground level +gme=.23; % gyro magnetic ration for exited level % CHECKME + +zeeman_splitting=0.0; +B_field=zeeman_splitting/gmg; + +%bottom level |F=1> +levels( 1)=struct( "ang_momentum", 0, "total_momentum", 1, "m", -1, "energy", 0, "gm", -gmg); +levels( 2)=struct( "ang_momentum", 0, "total_momentum", 1, "m", 0, "energy", 0, "gm", -gmg); +levels( 3)=struct( "ang_momentum", 0, "total_momentum", 1, "m", 1, "energy", 0, "gm", -gmg); + +%second bottom level |F=2> +levels( 4)=struct( "ang_momentum", 0, "total_momentum", 2, "m", -2, "energy", w_sf2, "gm", gmg); +levels( 5)=struct( "ang_momentum", 0, "total_momentum", 2, "m", -1, "energy", w_sf2, "gm", gmg); +levels( 6)=struct( "ang_momentum", 0, "total_momentum", 2, "m", 0, "energy", w_sf2, "gm", gmg); +levels( 7)=struct( "ang_momentum", 0, "total_momentum", 2, "m", 1, "energy", w_sf2, "gm", gmg); +levels( 8)=struct( "ang_momentum", 0, "total_momentum", 2, "m", 2, "energy", w_sf2, "gm", gmg); + +% first exited level |F=1> +levels( 9)=struct( "ang_momentum", 1, "total_momentum", 1, "m", -1, "energy", w_pf1, "gm", -gme); +levels(10)=struct( "ang_momentum", 1, "total_momentum", 1, "m", 0, "energy", w_pf1, "gm", -gme); +levels(11)=struct( "ang_momentum", 1, "total_momentum", 1, "m", 1, "energy", w_pf1, "gm", -gme); + +% second exited level |F=2> +levels(12)=struct( "ang_momentum", 1, "total_momentum", 2, "m", -2, "energy", w_pf2, "gm", gme); +levels(13)=struct( "ang_momentum", 1, "total_momentum", 2, "m", -1, "energy", w_pf2, "gm", gme); +levels(14)=struct( "ang_momentum", 1, "total_momentum", 2, "m", 0, "energy", w_pf2, "gm", gme); +levels(15)=struct( "ang_momentum", 1, "total_momentum", 2, "m", 1, "energy", w_pf2, "gm", gme); +levels(16)=struct( "ang_momentum", 1, "total_momentum", 2, "m", 2, "energy", w_pf2, "gm", gme); + +Nlevels=size(levels)(2); + + +H0=zeros(Nlevels); +energy = [1:Nlevels].*0; +ang_momentum = [1:Nlevels].*0; +total_momentum = [1:Nlevels].*0; +m = [1:Nlevels].*0; +gm = [1:Nlevels].*0; + +for i=1:Nlevels + energy(i) = levels(i).energy; + ang_momentum(i) = levels(i).ang_momentum; + total_momentum(i) = levels(i).total_momentum; + m(i) = levels(i).m; + gm(i) = levels(i).gm; +endfor +H0=diag(energy)*hbar; + + +dipole_elements.left = zeros(Nlevels); +dipole_elements.right = zeros(Nlevels); +dipole_elements.linear = zeros(Nlevels); +% define dipole elements for transition from level j->k +for j=1:Nlevels + for k=1:Nlevels + if ( abs(ang_momentum(j) - ang_momentum(k)) == 1) + %transition allowed for L =L' +/- 1 + % but they correct within a factor, but not sign + if ( ( H0(j,j) < H0(k,k)) ) + de=dipole_elementRb87D1line(... + total_momentum(j),m(j), ... + total_momentum(k),m(k) ... + ); + dipole_elements.left(j,k) = de.left; + dipole_elements.right(j,k) = de.right; + dipole_elements.linear(j,k) = de.linear; + endif + endif + endfor +endfor +dipole_elements.linear+=dipole_elements.linear'; +dipole_elements.left+=dipole_elements.left'; +dipole_elements.right+=dipole_elements.right'; + +maximum_dipole_elements=abs(dipole_elements.linear) + abs(dipole_elements.left) + abs(dipole_elements.right); + +%defasing matrix +g_deph=0; +g_dephasing=zeros(Nlevels); +% dephasing only for non zero dipole elements (am I right?) +g_dephasing=g_deph*(abs(maximum_dipole_elements) != 0); + +% decay matrix g(i,j) correspnds to decay from i-->j +gamma=6; +g_decay=zeros(Nlevels); +for i=1:Nlevels + for j=1:Nlevels + if ( H0(i,i) > H0(j,j) ) + % only upper levels decaying and decay is always positive + g_decay(i,j)=gamma * abs( maximum_dipole_elements(i,j) ); + endif + endfor +endfor + +% ground level mixing need to be artificial +gamma_hpf=.0001; +for i=1:Nlevels + for j=1:Nlevels + % it would be better to introduce a level corresponding to the bath + % but this slows calculations + % So + % ground hyperfine are equally mixed together + if ( (abs( H0(i,i) - H0(j,j)) == w_hpf_ground*hbar ) || ... + (abs( H0(i,i) - H0(j,j)) == 0 ) ) + % i and j correspond to 2 ground levels + % we cannot decay to itself + if ( i != j ) + % total eight ground levels F=2 and F=1 so we decay in 7 channels + g_decay(i,j)+=gamma_hpf/7; + endif + endif + endfor +endfor + +% apply B field Zeeman splitting +energy+=B_field * ( gm .* m); +% convert frequency to energy units +H0=diag(energy)*hbar; + +% vim: ts=2:sw=2:fdm=indent diff --git a/psr/useful_constants.m b/psr/useful_constants.m new file mode 100644 index 0000000..82d1d1a --- /dev/null +++ b/psr/useful_constants.m @@ -0,0 +1,6 @@ +1; + +% some physical constants +hbar=1; +im_one=0+1i; +el_charge=1; diff --git a/psr/useful_functions.m b/psr/useful_functions.m new file mode 100644 index 0000000..eb3e880 --- /dev/null +++ b/psr/useful_functions.m @@ -0,0 +1,337 @@ +1; + +function ret=decay_total(g_decay,i) +% calculate total decay for particular level taking in account all branches + ret=sum(g_decay(i,:)); +endfunction + +function ret=kron_delta(i,j) +% kroneker delta symbol + if ((i==j)) + ret=1; + else + ret=0; + endif +endfunction + +function rho=rhoOfFreq(rhoLiouville, freqIndex, Nlevels) +% this function create from Liouville density vector +% the density matrix with given modulation frequency + rho=zeros(Nlevels); + rho(:)=rhoLiouville((freqIndex-1)*Nlevels^2+1:(freqIndex)*Nlevels^2); + rho=rho.'; +endfunction + +function [N, rhoLiouville_w, rhoLiouville_r, rhoLiouville_c]=unfold_density_matrix(Nlevels,Nfreq) +% 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) + N = Nfreq*Nlevels*Nlevels; + rho_size = Nlevels*Nlevels; + rhoLiouville_w=zeros(N,1); + rhoLiouville_r=zeros(N,1); + rhoLiouville_c=zeros(N,1); + + w=1:Nfreq; + w_tmplate=(repmat(w,rho_size,1))(:); + rhoLiouville_w=w_tmplate; + r=1:Nlevels; + r_tmplate=(repmat(r,Nlevels,1))(:); + rhoLiouville_r=(repmat(r_tmplate,Nfreq,1))(:)'; + c=(1:Nlevels)';% hold column value of rho_rc + rhoLiouville_c=repmat(c,Nfreq*Nlevels,1); +endfunction + + +function [L0m, polarizability_m]=L0_and_polarization_submatrices( ... + Nlevels, ... + H0, g_decay, g_dephasing, dipole_elements ... + ) +% create (Nlevels*Nlevels)x*(Nlevels*Nlevels) +% sub matrices of Liouville operator +% which repeat themselves for each modulation frequency +% based on recipe from Eugeniy Mikhailov thesis + %------------------------- + useful_constants; + rho_size=Nlevels*Nlevels; + + % now we create Liouville indexes list + [Ndummy, rhoLiouville_w_notused, rhoLiouville_r, rhoLiouville_c]=unfold_density_matrix(Nlevels,1); + + kron_delta_m=eye(Nlevels); + % note that L0 and decay parts depend only on combination of indexes + % jk,mn but repeats itself for every frequency + L0m=zeros(rho_size); % (Nlevels^2)x(Nlevels^2) matrix + decay_part_m=zeros(rho_size); % (NxN)x(NxN) matrix + % polarization matrix will be multiplied by field amplitude letter + % polarization is part of perturbation part of Hamiltonian + polarizability_m.linear = zeros(rho_size); % (NxN)x(NxN) matrix + polarizability_m.left = zeros(rho_size); % (NxN)x(NxN) matrix + polarizability_m.right = zeros(rho_size); % (NxN)x(NxN) matrix + for p=1:rho_size + % p= j*Nlevels+k + % this might speed up stuff since less matrix passed back and force + j=rhoLiouville_r(p); + k=rhoLiouville_c(p); + for s=1:rho_size + % s= m*Nlevels+n + m=rhoLiouville_r(s); + n=rhoLiouville_c(s); + + % calculate unperturbed part (Hamiltonian without EM field) + L0m(p,s)=H0(j,m)*kron_delta_m(k,n)-H0(n,k)*kron_delta_m(j,m); + decay_part_m(p,s)= ... + ( ... + decay_total(g_decay,k)/2 ... + + decay_total(g_decay,j)/2 ... + + g_dephasing(j,k) ... + )* kron_delta_m(j,m)*kron_delta_m(k,n) ... + - kron_delta_m(m,n)*kron_delta_m(j,k)*g_decay(m,j) ; + polarizability_m.linear(p,s)= ( dipole_elements.linear(j,m)*kron_delta_m(k,n)-dipole_elements.linear(n,k)*kron_delta_m(j,m) ); + polarizability_m.left(p,s)= ( dipole_elements.left(j,m)*kron_delta_m(k,n)-dipole_elements.left(n,k)*kron_delta_m(j,m) ); + polarizability_m.right(p,s)= ( dipole_elements.right(j,m)*kron_delta_m(k,n)-dipole_elements.right(n,k)*kron_delta_m(j,m) ); + endfor + endfor + L0m=-im_one/hbar*L0m - decay_part_m; +endfunction + +function L=Liouville_operator_matrix( ... + N, ... + L0m, polarizability_m, ... + E_field, ... + modulation_freq, rhoLiouville_w, rhoLiouville_r, rhoLiouville_c ... + ) +% Liouville operator matrix construction +% based on recipe from Eugeniy Mikhailov thesis + %------------------------- + useful_constants; + L=zeros(N); % NxN matrix + Nfreq=length(modulation_freq); + + % Lets be supper smart and speed up L matrix construction + % since it has a lot of voids. + % By creation of rhoLiouville we know that there are + % consequent chunks of rho_ij modulated with same frequency + % this means that rhoLiouville is split in to Nfreq chunks + % with length Nlevels*Nlevels=N/Nfreq + rho_size=N/Nfreq; + + % creating building blocks of L by rho_size * rho_size + for w3i=1:Nfreq + w_iner=modulation_freq(w3i); + if ((w_iner == 0)) + % calculate unperturbed part (Hamiltonian without EM field) + L_sub{w3i}=L0m; + else + % calculate perturbed part (Hamiltonian with EM field) + % in other word interactive part of Hamiltonian + L_sub{w3i} = ... + -im_one/hbar*polarizability_m.linear * E_field.linear(w3i) ... + -im_one/hbar*polarizability_m.left * E_field.left(w3i) ... + -im_one/hbar*polarizability_m.right * E_field.right(w3i) ... + ; + endif + endfor + + % Liouville matrix operator has Nlevels*Nlevels blocks + % which governed by the same modulation frequency + for p_freq_cntr=1:Nfreq + p0=1+(p_freq_cntr-1)*rho_size; + % we guaranteed to know frequency of final and initial rhoLiouville + w1i=rhoLiouville_w(p0); % final + w_jk=modulation_freq(w1i); + for s_freq_cntr=1:Nfreq + s0=1+(s_freq_cntr-1)*rho_size; + w2i=rhoLiouville_w(s0); % initial + 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 frequency in the list of available frequencies + % but since we not guaranteed to find it lets assign temporary 0 to Liouville matrix element + w3i=(w_l == modulation_freq); + if (any(w3i)) + % yey, requested modulation frequency exist + % lets do L sub matrix filling + % at most we should have only one matching frequency + w_iner=modulation_freq(w3i); + L(p0:p0+rho_size-1,s0:s0+rho_size-1) = L_sub{w3i}; + + endif + endfor + % diagonal elements are self modulated + % due to rotating wave approximation + L(p0:p0+rho_size-1,p0:p0+rho_size-1)+= -im_one*w_jk*eye(rho_size); + endfor +endfunction + + +function [rhoLiouville_dot, L]=constrain_rho_and_match_L( ... + N, L, ... + modulation_freq, rhoLiouville_w, rhoLiouville_r, rhoLiouville_c) +% 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= 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 + +function kappa=susceptibility(wi, rhoLiouville, dipole_elements, E_field) +% calculate susceptibility for the field at given frequency index + Nlevels=( size(dipole_elements.linear)(1) ); + rho=rhoOfFreq(rhoLiouville, wi, Nlevels); + kappa.linear=0; + kappa.left=0; + kappa.right=0; + + kappa.linear = sum( sum( transpose(dipole_elements.linear) .* rho ) ); + kappa.left = sum( sum( transpose(dipole_elements.left) .* rho ) ); + kappa.right = sum( sum( transpose(dipole_elements.right) .* rho ) ); + + kappa.linear /= E_field.linear( wi ); + kappa.left /= E_field.left( wi ); + kappa.right /= E_field.right( wi ); +endfunction + +function index=freq2index(freq, modulation_freq) +% convert modulation freq to its index in the modulation_freq vector + index=[1:length(modulation_freq)](modulation_freq==freq); +endfunction + +function rhoLiouville=rhoLiouville_steady_state(L0m, polarizability_m, E_field, modulation_freq) +% calculates rhoLiouville vector assuming steady state situation and normalization of rho_ii to 1 + Nlevels=sqrt( size(L0m)(1) ); + Nfreq=length(modulation_freq); + + % now we create Liouville indexes list + [N, rhoLiouville_w, rhoLiouville_r, rhoLiouville_c]=unfold_density_matrix(Nlevels,Nfreq); + + % Liouville operator matrix construction + L=Liouville_operator_matrix( + N, + L0m, polarizability_m, + E_field, + modulation_freq, rhoLiouville_w, rhoLiouville_r, rhoLiouville_c + ); + + %use the fact that sum(rho_ii)=1 to constrain solution + [rhoLiouville_dot, L]=constrain_rho_and_match_L( + N, L, + modulation_freq, rhoLiouville_w, rhoLiouville_r, rhoLiouville_c); + + %solving for density matrix vector + rhoLiouville=L\rhoLiouville_dot; +endfunction + +function [xi_linear, xi_left, xi_right]=susceptibility_steady_state_at_freq( atom_field_problem) + % find steady state susceptibility at particular modulation frequency element + % at given E_field + global atom_properties; + L0m = atom_properties.L0m ; + polarizability_m = atom_properties.polarizability_m ; + dipole_elements = atom_properties.dipole_elements ; + + E_field = atom_field_problem.E_field ; + modulation_freq = atom_field_problem.modulation_freq ; + freq_index = atom_field_problem.freq_index ; + + rhoLiouville=rhoLiouville_steady_state(L0m, polarizability_m, E_field, modulation_freq); + xi=susceptibility(freq_index, rhoLiouville, dipole_elements, E_field); + xi_linear = xi.linear; + xi_right = xi.right; + xi_left = xi.left; +endfunction + +function [dEdz_coef_linear, dEdz_coef_left, dEdz_coef_right] =dEdz_at_freq(wi, rhoLiouville, dipole_elements, E_field) +% complex absorption coefficient +% at given E_field frequency component + Nlevels=( size(dipole_elements.linear)(1) ); + rho=rhoOfFreq(rhoLiouville, wi, Nlevels); + + dEdz_coef_linear = sum( sum( transpose(dipole_elements.linear) .* rho ) ); + dEdz_coef_left = sum( sum( transpose(dipole_elements.left) .* rho ) ); + dEdz_coef_right = sum( sum( transpose(dipole_elements.right) .* rho ) ); + +endfunction + +function [dEdz_linear, dEdz_left, dEdz_right]=dEdz( atom_field_problem) +% complex absorption coefficient for each field + global atom_properties; + L0m = atom_properties.L0m ; + polarizability_m = atom_properties.polarizability_m ; + dipole_elements = atom_properties.dipole_elements ; + + E_field = atom_field_problem.E_field ; + modulation_freq = atom_field_problem.modulation_freq ; + Nfreq=length(modulation_freq); + + rhoLiouville=rhoLiouville_steady_state(L0m, polarizability_m, E_field, modulation_freq); + for wi=1:Nfreq + [dEdz_linear(wi), dEdz_left(wi), dEdz_right(wi)] = dEdz_at_freq(wi, rhoLiouville, dipole_elements, E_field); + endfor +endfunction + +function relative_transmission=total_relative_transmission(atom_field_problem) +% summed across all frequencies field absorption coefficient + global atom_properties; + [dEdz_linear, dEdz_left, dEdz_right]=dEdz( atom_field_problem); + %dEdz_total= dEdz_linear .* conj(dEdz_linear) ... + %+dEdz_left .* conj(dEdz_left) ... + %+dEdz_right .* conj(dEdz_right); + %total_absorption = sum(dEdz_total); + + %total_absorption = |E|^2 - | E - dEdz | ^2 + E_field.linear = atom_field_problem.E_field.linear; + E_field.right = atom_field_problem.E_field.right; + E_field.left = atom_field_problem.E_field.left; + + modulation_freq = atom_field_problem.modulation_freq ; + pos_freq_indexes=(modulation_freq>0); + % WARNING INTRODUCED HERE BUT MUST BE DEFINE IN ATOM PROPERTIES FILE + %n_atoms - proportional to a number of interacting atoms + n_atoms=500; + transmited_intensities_vector = ... + abs(E_field.linear + n_atoms*(1i)*dEdz_linear).^2 ... + +abs(E_field.right + n_atoms*(1i)*dEdz_right).^2 ... + +abs(E_field.left + n_atoms*(1i)*dEdz_left).^2; + transmited_intensities_vector = transmited_intensities_vector(pos_freq_indexes); + input_intensities_vector = ... + abs(E_field.linear).^2 ... + +abs(E_field.right).^2 ... + +abs(E_field.left).^2; + input_intensities_vector = input_intensities_vector(pos_freq_indexes); + + relative_transmission = sum(transmited_intensities_vector) / sum(input_intensities_vector); +endfunction + +% create full list of atom modulation frequencies from positive light frequency amplitudes +function [modulation_freq, E_field_amplitudes] = ... +light_positive_frequencies_and_amplitudes2full_set_of_modulation_frequencies_and_amlitudes(... + positive_light_frequencies, positive_light_field_amplitudes ) + % we should add 0 frequency as first element of our frequencies list + modulation_freq = cat(2, 0, positive_light_frequencies, -positive_light_frequencies); + % negative frequencies have complex conjugated light fields amplitudes + E_field_amplitudes.left = cat(2, 0, positive_light_field_amplitudes.left, conj(positive_light_field_amplitudes.left) ); + E_field_amplitudes.right = cat(2, 0, positive_light_field_amplitudes.right, conj(positive_light_field_amplitudes.right) ); + E_field_amplitudes.linear = cat(2, 0, positive_light_field_amplitudes.linear, conj(positive_light_field_amplitudes.linear) ); +endfunction + + + +% vim: ts=2:sw=2:fdm=indent |