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Modifications to have only width of Gaussian ansatz as the variational parameter and other changes to keep consistent with the source code as written originally by Wyatt.

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Karthik 2024-11-15 14:33:46 +01:00
parent 968467a186
commit b3ab383300
12 changed files with 63 additions and 72 deletions
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7
Dipolar-Gas-Simulator/+BdGSolver2D/solveBogoliubovdeGennesIn2D.m
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@ -1,16 +1,15 @@
function [evals, modes] = solveBogoliubovdeGennesIn2D(psi, Params, VDk, VParams, Transf, muchem)
wz_tilde = Params.wz / Params.w0;
gs = Params.gs;
gdd = Params.gdd;
gammaQF = Params.gammaQF;
KEop = 0.5*(Transf.KX.^2+Transf.KY.^2);
Ez = (0.25*VParams.sigma^2) + (0.25*wz_tilde^2*VParams.sigma^2);
Ez = (0.25*VParams.ell^2) + (0.25*Params.gz*VParams.ell^2);
muchem_tilde = muchem - Ez;
g_pf_2D = 1/(sqrt(2*pi)*VParams.sigma);
gQF_pf_2D = sqrt(2/5)/(pi^(3/4)*VParams.sigma^(3/2));
g_pf_2D = 1/(sqrt(2*pi)*VParams.ell);
gQF_pf_2D = sqrt(2/5)/(pi^(3/4)*VParams.ell^(3/2));
% eigs only works with column vectors
psi = psi.';

4
Dipolar-Gas-Simulator/+Scripts/run_locally.m
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@ -59,7 +59,7 @@ OptionsStruct.ScatteringLength = 102.515;
OptionsStruct.TrapFrequencies = [10, 10, 72.4];
OptionsStruct.NumberOfGridPoints = [1024, 1024];
OptionsStruct.NumberOfGridPoints = [128, 128];
OptionsStruct.Dimensions = [100, 100];
OptionsStruct.TimeStepSize = 1E-3; % in s
OptionsStruct.TimeCutOff = 2E6; % in s
@ -73,7 +73,7 @@ OptionsStruct.SaveDirectory = './Data';
options = Helper.convertstruct2cell(OptionsStruct);
clear OptionsStruct
solver = Variational2D.DipolarGas(options{:});
solver = VariationalSolver2D.DipolarGas(options{:});
%-% Run Solver %-%
[Params, Transf, psi, V, VDk] = solver.run();

4
Dipolar-Gas-Simulator/+Scripts/run_on_cluster.m
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@ -9,7 +9,7 @@ OptionsStruct.ScatteringLength = 102.515;
OptionsStruct.TrapFrequencies = [10, 10, 72.4];
OptionsStruct.NumberOfGridPoints = [1024, 1024];
OptionsStruct.NumberOfGridPoints = [128, 128];
OptionsStruct.Dimensions = [100, 100];
OptionsStruct.TimeStepSize = 1E-3; % in s
OptionsStruct.TimeCutOff = 2E6; % in s
@ -23,7 +23,7 @@ OptionsStruct.SaveDirectory = './Data';
options = Helper.convertstruct2cell(OptionsStruct);
clear OptionsStruct
solver = Variational2D.DipolarGas(options{:});
solver = VariationalSolver2D.DipolarGas(options{:});
%-% Run Solver %-%
[Params, Transf, psi, V, VDk] = solver.run();

10
Dipolar-Gas-Simulator/+VariationalSolver2D/@Calculator/calculateChemicalPotential.m
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@ -1,8 +1,8 @@
function muchem = calculateChemicalPotential(~,psi,Params,VParams,Transf,VDk,V)
g_eff = Params.gs*VParams.nu/(2^(1+1/VParams.nu)*VParams.ell*gamma(1/VParams.nu));
gamma_eff = Params.gammaQF*2^(1/VParams.nu-1.5)*5^(-1/VParams.nu)*VParams.ell*gamma(1+1/VParams.nu)*( VParams.nu/(VParams.ell*gamma(1/VParams.nu)) )^(5/2);
EVar = VParams.nu^2*gamma(2-1/VParams.nu)/(8*VParams.ell^2*gamma(1/VParams.nu)) + 0.5*Params.gz*VParams.ell^2*gamma(3/VParams.nu)/gamma(1/VParams.nu);
g_eff = Params.gs * (1/(sqrt(2*pi)*VParams.ell));
gamma_eff = Params.gammaQF * (sqrt(2/5)/(pi^(3/4)*VParams.ell^(3/2)));
Ez = (0.25*VParams.ell^2) + (0.25*Params.gz*VParams.ell^2);
% Parameters
normfac = Params.Lx*Params.Ly/numel(psi);
@ -11,7 +11,7 @@ function muchem = calculateChemicalPotential(~,psi,Params,VParams,Transf,VDk,V)
% DDIs
frho = fftn(abs(psi).^2);
Phi = real(ifftn(frho.*VDk));
Eddi = (Params.gdd*Phi.*abs(psi).^2)/(sqrt(2*pi)*VParams.ell_eff);
Eddi = (Params.gdd*Phi.*abs(psi).^2)/(sqrt(2*pi)*VParams.ell);
%Kinetic energy
Ekin = KEop.*abs(fftn(psi)*normfac).^2;
@ -27,6 +27,6 @@ function muchem = calculateChemicalPotential(~,psi,Params,VParams,Transf,VDk,V)
Eqf = gamma_eff*abs(psi).^5;
%Total energy
muchem = Ekin + EVar*Params.N + trapz(Epot(:) + Eint(:) + Eddi(:) + Eqf(:))*Transf.dx*Transf.dy; %
muchem = Ekin + Ez*Params.N + trapz(Epot(:) + Eint(:) + Eddi(:) + Eqf(:))*Transf.dx*Transf.dy; %
muchem = muchem / Params.N; %Only use if psi is normalized to N
end

10
Dipolar-Gas-Simulator/+VariationalSolver2D/@Calculator/calculateNormalizedResiduals.m
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@ -1,15 +1,15 @@
function res = calculateNormalizedResiduals(~,psi,Params,VParams,Transf,VDk,V,muchem)
g_eff = Params.gs*VParams.nu/(2^(1+1/VParams.nu)*VParams.ell*gamma(1/VParams.nu));
gamma_eff = Params.gammaQF*2^(1/VParams.nu-1.5)*5^(-1/VParams.nu)*VParams.ell*gamma(1+1/VParams.nu)*( VParams.nu/(VParams.ell*gamma(1/VParams.nu)) )^(5/2);
EVar = VParams.nu^2*gamma(2-1/VParams.nu)/(8*VParams.ell^2*gamma(1/VParams.nu)) + 0.5*Params.gz*VParams.ell^2*gamma(3/VParams.nu)/gamma(1/VParams.nu);
g_eff = Params.gs * (1/(sqrt(2*pi)*VParams.ell));
gamma_eff = Params.gammaQF * (sqrt(2/5)/(pi^(3/4)*VParams.ell^(3/2)));
Ez = (0.25*VParams.ell^2) + (0.25*Params.gz*VParams.ell^2);
KEop = 0.5*(Transf.KX.^2+Transf.KY.^2);
% DDIs
frho = fftn(abs(psi).^2);
Phi = real(ifftn(frho.*VDk));
Eddi = Params.gdd*Phi.*psi/(sqrt(2*pi)*VParams.ell_eff);
Eddi = Params.gdd*Phi.*psi/(sqrt(2*pi)*VParams.ell);
% Kinetic energy
Ekin = ifftn(KEop.*fftn(psi));
@ -24,6 +24,6 @@ function res = calculateNormalizedResiduals(~,psi,Params,VParams,Transf,VDk,V,m
Eqf = gamma_eff*abs(psi).^3.*psi;
% Total energy
res = trapz(abs(Ekin(:) + EVar*psi(:) + Epot(:) + Eint(:) + Eddi(:) + Eqf(:) - muchem*psi(:))*Transf.dx*Transf.dy)/trapz(abs(muchem*psi(:))*Transf.dx*Transf.dy);
res = trapz(abs(Ekin(:) + Ez*psi(:) + Epot(:) + Eint(:) + Eddi(:) + Eqf(:) - muchem*psi(:))*Transf.dx*Transf.dy)/trapz(abs(muchem*psi(:))*Transf.dx*Transf.dy);
end

10
Dipolar-Gas-Simulator/+VariationalSolver2D/@Calculator/calculateTotalEnergy.m
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@ -1,8 +1,8 @@
function E = calculateTotalEnergy(~,psi,Params,VParams,Transf,VDk,V)
g_eff = Params.gs*VParams.nu/(2^(1+1/VParams.nu)*VParams.ell*gamma(1/VParams.nu));
gamma_eff = Params.gammaQF*2^(1/VParams.nu-1.5)*5^(-1/VParams.nu)*VParams.ell*gamma(1+1/VParams.nu)*( VParams.nu/(VParams.ell*gamma(1/VParams.nu)) )^(5/2);
EVar = VParams.nu^2*gamma(2-1/VParams.nu)/(8*VParams.ell^2*gamma(1/VParams.nu)) + 0.5*Params.gz*VParams.ell^2*gamma(3/VParams.nu)/gamma(1/VParams.nu);
g_eff = Params.gs * (1/(sqrt(2*pi)*VParams.ell));
gamma_eff = Params.gammaQF * (sqrt(2/5)/(pi^(3/4)*VParams.ell^(3/2)));
Ez = (0.25*VParams.ell^2) + (0.25*Params.gz*VParams.ell^2);
% Parameters
KEop = 0.5*(Transf.KX.^2+Transf.KY.^2);
@ -11,7 +11,7 @@ function E = calculateTotalEnergy(~,psi,Params,VParams,Transf,VDk,V)
% DDIs
frho = fftn(abs(psi).^2);
Phi = real(ifftn(frho.*VDk));
Eddi = 0.5*Params.gdd*Phi.*abs(psi).^2/(sqrt(2*pi)*VParams.ell_eff);%
Eddi = 0.5*Params.gdd*Phi.*abs(psi).^2/(sqrt(2*pi)*VParams.ell);%
Eddi = trapz(Eddi(:))*Transf.dx*Transf.dy;
% Kinetic energy
@ -30,5 +30,5 @@ function E = calculateTotalEnergy(~,psi,Params,VParams,Transf,VDk,V)
Eqf = 0.4*gamma_eff*abs(psi).^5;
Eqf = trapz(Eqf(:))*Transf.dx*Transf.dy;
E = EVar*Params.N + Ekin + Epot + Eint + Eddi + Eqf;
E = Ez*Params.N + Ekin + Epot + Eint + Eddi + Eqf;
end

4
Dipolar-Gas-Simulator/+VariationalSolver2D/@Calculator/calculateVDkWithCutoff.m
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@ -2,8 +2,8 @@ function VDk = calculateVDkWithCutoff(~, rcut, Transf, Params, VParams)
% == Calculating the DDI potential in Fourier space with appropriate cutoff == %
% Interaction in K space
QX = Transf.KX*VParams.ell_eff/sqrt(2);
QY = Transf.KY*VParams.ell_eff/sqrt(2);
QX = Transf.KX*VParams.ell/sqrt(2);
QY = Transf.KY*VParams.ell/sqrt(2);
Qsq = QX.^2 + QY.^2;
absQ = sqrt(Qsq);

17
Dipolar-Gas-Simulator/+VariationalSolver2D/@Calculator/calculateVariationalEnergy.m
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@ -1,21 +1,17 @@
function E = calculateVariationalEnergy(this, psi, Params, VarArray, Transf, VDk, V)
function E = calculateVariationalEnergy(~, psi, Params, ell, Transf, VDk, V)
VParams.ell = VarArray(1);
VParams.nu = VarArray(2);
g_eff = Params.gs*VParams.nu/(2^(1+1/VParams.nu)*VParams.ell*gamma(1/VParams.nu));
gamma_eff = Params.gammaQF*2^(1/VParams.nu-1.5)*5^(-1/VParams.nu)*VParams.ell*gamma(1+1/VParams.nu)*( VParams.nu/(VParams.ell*gamma(1/VParams.nu)) )^(5/2);
EVar = VParams.nu^2*gamma(2-1/VParams.nu)/(8*VParams.ell^2*gamma(1/VParams.nu)) + 0.5*Params.gz*VParams.ell^2*gamma(3/VParams.nu)/gamma(1/VParams.nu);
g_eff = Params.gs * (1/(sqrt(2*pi)*ell));
gamma_eff = Params.gammaQF * (sqrt(2/5)/(pi^(3/4)*ell^(3/2)));
Ez = (0.25*ell^2) + (0.25*Params.gz*ell^2);
% Parameters
KEop = 0.5*(Transf.KX.^2+Transf.KY.^2);
normfac = Params.Lx*Params.Ly/numel(psi);
% DDIs
[VParams] = this.find_nk_fit(VParams); % Not totally sure this should be here
frho = fftn(abs(psi).^2);
Phi = real(ifftn(frho.*VDk));
Eddi = 0.5*Params.gdd*Phi.*abs(psi).^2/(sqrt(2*pi)*VParams.ell_eff);%
Eddi = 0.5*Params.gdd*Phi.*abs(psi).^2/(sqrt(2*pi)*ell);%
Eddi = sum(Eddi(:))*Transf.dx*Transf.dy;
% Kinetic energy
@ -35,5 +31,6 @@ function E = calculateVariationalEnergy(this, psi, Params, VarArray, Transf, VDk
Eqf = trapz(Eqf(:))*Transf.dx*Transf.dy;
% Total
E = EVar*Params.N + Ekin + Epot + Eint + Eddi + Eqf;
E = Ez*Params.N + Ekin + Epot + Eint + Eddi + Eqf;
end

2
Dipolar-Gas-Simulator/+VariationalSolver2D/@DipolarGas/DipolarGas.m
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@ -90,7 +90,7 @@ classdef DipolarGas < handle & matlab.mixin.Copyable
this.DoSave = p.Results.SaveData;
this.SaveDirectory = p.Results.SaveDirectory;
this.Calculator = Variational2D.Calculator();
this.Calculator = VariationalSolver2D.Calculator();
this.SimulationParameters = this.setupParameters();

8
Dipolar-Gas-Simulator/+VariationalSolver2D/@DipolarGas/propagateWavefunction.m
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@ -22,9 +22,9 @@ function [psi] = propagateWavefunction(this, psi, Params, VParams, Transf, VDk,
res = this.Calculator.calculateNormalizedResiduals(psi,Params,VParams,Transf,VDk,V,muchem);
Observ.residual = [Observ.residual res];
g_eff = Params.gs*VParams.nu/(2^(1+1/VParams.nu)*VParams.ell*gamma(1/VParams.nu));
gamma_eff = Params.gammaQF*2^(1/VParams.nu-1.5)*5^(-1/VParams.nu)*VParams.ell*gamma(1+1/VParams.nu)*( VParams.nu/(VParams.ell*gamma(1/VParams.nu)) )^(5/2);
EVar = VParams.nu^2*gamma(2-1/VParams.nu)/(8*VParams.ell^2*gamma(1/VParams.nu)) + 0.5*Params.gz*VParams.ell^2*gamma(3/VParams.nu)/gamma(1/VParams.nu);
g_eff = Params.gs * (1/(sqrt(2*pi)*VParams.ell));
gamma_eff = Params.gammaQF * (sqrt(2/5)/(pi^(3/4)*VParams.ell^(3/2)));
Ez = (0.25*VParams.ell^2) + (0.25*Params.gz*VParams.ell^2);
pb = Helper.ProgressBar();
pb.run('Propagating in imaginary time: ');
@ -41,7 +41,7 @@ function [psi] = propagateWavefunction(this, psi, Params, VParams, Transf, VDk,
Phi = real(ifftn(frho.*VDk));
% Real-space
psi = psi.*exp(-1i*dt*(V + EVar + g_eff*abs(psi).^2 + gamma_eff*abs(psi).^3 + Params.gdd*Phi/(sqrt(2*pi)*VParams.ell_eff) - muchem));
psi = psi.*exp(-1i*dt*(V + Ez + g_eff*abs(psi).^2 + gamma_eff*abs(psi).^3 + Params.gdd*Phi/(sqrt(2*pi)*VParams.ell) - muchem));
% kin
psi = fftn(psi);

43
Dipolar-Gas-Simulator/+VariationalSolver2D/@DipolarGas/run.m
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@ -9,10 +9,15 @@ function [Params, Transf, psi, V, VDk] = run(this)
[Transf] = this.setupSpace(Params);
% --- Set up for Variational method ---
VarArray = Params.VarArray;
VParams.ell = VarArray(1);
VParams.nu = VarArray(2);
[VParams] = this.Calculator.find_nk_fit(VParams);
VParams.SelfConIter = Params.SelfConIter; % Max number of iterations to perform self-consistent calculation
VParams.ell = Params.ell; % initial [ell], ell is the "width" - psi ~ e^(z^2/ell^2)
% Window of optimization
VParams.ell_lower = Params.ell_lower;
VParams.ell_upper = Params.ell_upper;
% Relative cutoffs
VParams.ellcutoff = Params.ellcutoff;
% --- Initialize ---
mkdir(sprintf(this.SaveDirectory))
@ -21,24 +26,22 @@ function [Params, Transf, psi, V, VDk] = run(this)
[psi,V,VDk] = this.initialize(Params,VParams,Transf);
ells(1) = VarArray(1);
nus(1) = VarArray(2);
ells(1) = VParams.ell;
E_Var = @(x) this.Calculator.calculateVariationalEnergy(psi, Params, x, Transf, VDk, V)/Params.N;
E_vs_iter(1) = E_Var([ells(1) nus(1)]);
E_vs_iter(1) = E_Var(ells(1));
t_idx = 1; % Start at t = 0;
for nn = 1:Params.SelfConIter
Observ.EVec = []; Observ.NormVec = []; Observ.PCVec = []; Observ.tVecPlot = []; Observ.mucVec = []; Observ.residual = [];
Observ.res_idx = 1;
Observ.res_idx = 1;
VParams.ell = VarArray(1);
VParams.nu = VarArray(2);
[VParams] = this.Calculator.find_nk_fit(VParams);
[psi,V,VDk] = this.initialize(Params,VParams,Transf);
[~,V,VDk] = this.initialize(Params,VParams,Transf); % Do not overwrite psi, susbequent iterations should use psi generated at the end of the loop to converge faster
% This is still needed however to recalculate VDk with new value
% for the variational parameter
% --- Adding some noise ---
% Noise added in every iteration to ensure it is not stuck in some local minimum
Norm = trapz(abs(psi(:)).^2)*Transf.dx*Transf.dy; % normalisation
psi = sqrt(Params.N)*psi/sqrt(Norm);
r = normrnd(0,1,size(psi));
@ -52,24 +55,22 @@ function [Params, Transf, psi, V, VDk] = run(this)
% --- Constrained minimization ---
E_Var = @(x) this.Calculator.calculateVariationalEnergy(psi, Params, x, Transf, VDk, V)/Params.N;
VarArray = fmincon(E_Var,VarArray,[],[],[],[],[Params.ell_lower, Params.nu_lower],[Params.ell_upper, Params.nu_upper],[],fminconoptions);
VParams.ell = fmincon(E_Var,VParams.ell,[],[],[],[],Params.ell_lower,Params.ell_upper,[],fminconoptions);
% --- Convergence check ---
ells = [ells VarArray(1)];
nus = [nus VarArray(2)];
ells = [ells VParams.ell];
relelldiff = abs(ells(nn+1)-ells(nn))/ells(nn);
relnudiff = abs(nus(nn+1)-nus(nn))/nus(nn);
E_vs_iter = [E_vs_iter E_Var(VarArray)];
E_vs_iter = [E_vs_iter E_Var(VParams.ell)];
save(sprintf('./Data/Run_%03i/psi_gs_%i.mat',Params.njob),'psi','Observ','Transf','Params','VDk','V','VarArray');
save(sprintf('./Data/Run_%03i/psi_gs_%i.mat',Params.njob),'psi','Observ','Transf','Params','VDk','V','VParams');
if relelldiff < Params.ellcutoff && relnudiff < Params.nucutoff
if relelldiff < Params.ellcutoff
break
end
end
disp('Saving data...');
save(sprintf('./Data/Run_%03i/psi_gs.mat',Params.njob),'psi','Observ','Transf','Params','VDk','V','VarArray');
save(sprintf('./Data/Run_%03i/psi_gs.mat',Params.njob),'psi','Observ','Transf','Params','VDk','V','VParams');
disp('Save complete!');
delete(sprintf('./Data/Run_%03i/psi_gs_*.mat',Params.njob))

8
Dipolar-Gas-Simulator/+VariationalSolver2D/@DipolarGas/setupParameters.m
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@ -52,20 +52,14 @@ function [Params] = setupParameters(this)
% ================ Variational method parameters ================ %
% FMinCon Settings
Params.SelfConIter = 20; % Max number of iterations to perform self-consistent calculation
Params.VarArray = [4 2.5]; % initial [ell nu], expand for other params
% ell is the "width" and nu is the exponent. psi~ e^(z/ell)^nu
Params.ell = 4; % initial [ell], ell is the "width" - psi ~ e^(z^2/ell^2)
% Window of optimization
Params.ell_lower = 0.2;
Params.ell_upper = 12;
Params.nu_lower = 1;
Params.nu_upper = 4;
% Relative cutoffs
Params.ellcutoff = 1e-2;
Params.nucutoff = 1e-2;
% ================ Parameters defined by those above ================ %