Calculations/Dipolar-Gas-Simulator/+VariationalSolver2D/@DipolarGas/setupParameters.m

function [Params]  = setupParameters(this)
    CONSTANTS      = Helper.PhysicsConstants;
    hbar           = CONSTANTS.PlanckConstantReduced; % [J.s]
    kbol           = CONSTANTS.BoltzmannConstant;     % [J/K]
    mu0            = CONSTANTS.VacuumPermeability;    % [N/A^2]
    muB            = CONSTANTS.BohrMagneton;          % [J/T]
    a0             = CONSTANTS.BohrRadius;            % [m]
    m0             = CONSTANTS.AtomicMassUnit;        % [kg]
    w0             = 2*pi*100;                        % Angular frequency unit [s^-1]
    mu0factor      = 0.3049584233607396;              % =(m0/me)*pi*alpha^2 -- me=mass of electron, alpha=fine struct. const.
                                                      % mu0=mu0factor *hbar^2*a0/(m0*muB^2)
    % Number of points in each direction
    Params.Nx      = this.NumberOfGridPoints(1);
    Params.Ny      = this.NumberOfGridPoints(2);
    
    % Dimensions (in units of l0)
    Params.Lx      = this.Dimensions(1);
    Params.Ly      = this.Dimensions(2);
    
    % Mass, length scale
    Params.m       = CONSTANTS.Dy164Mass;
    l0             = sqrt(hbar/(Params.m*w0)); % Defining a harmonic oscillator length
    
    % Atom numbers
    Params.N       = this.NumberOfAtoms;
    
    % Dipole angle
    Params.theta   = this.DipolarPolarAngle;   % pi/2 dipoles along x, theta=0 dipoles along z 
    Params.phi     = this.DipolarAzimuthAngle;
    
    % Dipole lengths (units of muB)
    Params.mu      = CONSTANTS.DyMagneticMoment;
    
    % Scattering lengths
    Params.as      = this.ScatteringLength*a0;
    
    % Trapping frequencies
    Params.wx      = 2*pi*this.TrapFrequencies(1);
    Params.wy      = 2*pi*this.TrapFrequencies(2);
    Params.wz      = 2*pi*this.TrapFrequencies(3);
    
    % Tolerances
    Params.Etol             = this.EnergyTolerance;   
    Params.rtol             = this.ResidualTolerance;   
    Params.sim_time_cut_off = this.TimeCutOff;                 % sometimes the imaginary time gets a little stuck
                                                               % even though the solution is good, this just stops it going on forever
    Params.mindt            = this.MinimumTimeStepSize;        % Minimum size for a time step using adaptive dt

    Params.njob             = this.JobNumber;
    

    % ================ Variational method parameters ================ %
    % FMinCon Settings
    Params.SelfConIter = 20;      % Max number of iterations to perform self-consistent calculation
    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;
    
    % Relative cutoffs
    Params.ellcutoff   = 1e-2;

    % ================ Parameters defined by those above ================ %
    
    % Contact interaction strength (units of l0/m)
    Params.gs      = 4*pi*Params.as/l0;
    
    % Dipole lengths
    Params.add     = mu0*Params.mu^2*Params.m/(12*pi*hbar^2);
    
    % DDI strength
    Params.gdd     = 12*pi*Params.add/l0; %sometimes the 12 is a 4 --> depends on how Vdk (DDI) is defined
    
    % Trap gamma
    Params.gx      = (Params.wx/w0)^2;
    Params.gy      = (Params.wy/w0)^2;
    Params.gz      = (Params.wz/w0)^2;
    
    % == Calculate LHY correction to account for quantum fluctuations == %
    
    eps_dd = Params.add/Params.as;
    if eps_dd == 0
        Q5 = 1;
    elseif eps_dd == 1
        Q5 = 3*sqrt(3)/2;
    else
        yeps = (1-eps_dd)/(3*eps_dd);
        Q5 = (3*eps_dd)^(5/2)*( (8+26*yeps+33*yeps^2)*sqrt(1+yeps) + 15*yeps^3*log((1+sqrt(1+yeps))/sqrt(yeps)) )/48;
        Q5 = real(Q5);
    end
    
    Params.gammaQF = 128/3*sqrt(pi*(Params.as/l0)^5)*Q5;
    
    % Loading the rest into Params
    Params.hbar    = hbar; 
    Params.kbol    = kbol; 
    Params.mu0     = mu0; 
    Params.muB     = muB; 
    Params.a0      = a0;
    Params.w0      = w0; 
    Params.l0      = l0;
end