add examples

example/Example_SimStack_GaAs-AlAs-SL.m

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+ %{ 
+ %  This file is part of the SimStack distribution (https://github.com/laclaro/simstack).
+ %  Copyright (c) 2020 Henning Hollermann.
+ %  
+ %  This program is free software: you can redistribute it and/or modify  
+ %  it under the terms of the GNU General Public License as published by  
+ %  the Free Software Foundation, version 3.
+ % 
+ %  This program is distributed in the hope that it will be useful, but 
+ %  WITHOUT ANY WARRANTY; without even the implied warranty of 
+ %  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 
+ %  General Public License for more details.
+ % 
+ %  You should have received a copy of the GNU General Public License 
+ %  along with this program. If not, see <http://www.gnu.org/licenses/>.
+ %
+ %  Example for the usage of buildStack and SimStack simulating diffraction
+ %  at a perfect superlattice of 10x[8 GaAs / 4 AlAs].
+ %}
+
+clear all
+close all
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% load classes SimStack and buildStack
+addpath(genpath('/path/to/SimStack'))
+
+c_GaAs = 5.6537; % in anstroms
+c_AlAs = 5.6620; % in anstroms
+
+% build perfect SL stack with 10x[8 GaAs / 4 AlAs]
+SLStack = buildStack;
+% used building blocks are defined as functions within the class
+% they define the 'zpos' of the 'elements' in absolute coordinates
+% scaled by the given c lattice parameter
+% 'space' is the absolute distance to the subsequent block
+block_GaAs = SLStack.GaAs(c_GaAs);
+block_AlAs = SLStack.AlAs(c_AlAs);
+% add GaAs 8 GaAs blocks with in total 16 atoms
+SLStack.multiaddBlock(block_GaAs,8)
+% add AlAs layer
+SLStack.multiaddBlock(block_AlAs,4);
+% simulation space
+Qz=3:0.0001:6;
+% create SimStack object with 10 unit cells
+SLSim = SimStack('qz',Qz,'corr','none','n_UC',10);
+% add SL stack
+SLSim.addStructure(SLStack);
+% calculate all quantities including the added structure
+SLSim.update; 
+% plot result
+SLSim.plot;
+

example/Example_SimStack_GeTe-Sb2Te3-SL-block-variation.m

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+ %{ 
+ %  This file is part of the SimStack distribution (https://github.com/laclaro/simstack).
+ %  Copyright (c) 2020 Henning Hollermann.
+ %  
+ %  This program is free software: you can redistribute it and/or modify  
+ %  it under the terms of the GNU General Public License as published by  
+ %  the Free Software Foundation, version 3.
+ % 
+ %  This program is distributed in the hope that it will be useful, but 
+ %  WITHOUT ANY WARRANTY; without even the implied warranty of 
+ %  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 
+ %  General Public License for more details.
+ % 
+ %  You should have received a copy of the GNU General Public License 
+ %  along with this program. If not, see <http://www.gnu.org/licenses/>.
+ %
+ %  Example for the usage of buildStack and SimStack simulating diffraction
+ %  at superlattice of 10x[6 nm Sb2Te3 / 1 nm GeTe].
+ %}
+
+
+clear all
+close all
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% load classes
+addpath(genpath('D:\Science Data\Projects\Software Development\Matlab'));
+
+% Change the current folder to the folder of this m-file.
+if(~isdeployed)
+  cd(fileparts(which(mfilename)));
+end
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Simulation range, x axis in A^-1
+Qz = 1:0.0002:6;
+
+% lattice constants of the constituents
+c_Sb2Te3 = 30.5287;
+c_GeTe = 10.6917;
+% thicknesses of the building blocks
+t_QL = c_Sb2Te3/3;
+t_BL = c_GeTe/3;
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% stack definition
+
+% number of superposed random structures
+n_struct = 20;
+% CSL repetitions
+repetitions = 10;
+% sample definition
+n_QL = 6;
+n_BL = 3;
+% sigma about which the number of building blocks are allowed to vary
+s_QL = 1.5;
+s_BL = 1.5;
+% calculate SL BiLayer Thickness
+lambda_sim = n_QL*t_QL + n_BL*t_BL;
+eta_sim = n_QL*t_QL/lambda_sim;
+t_sim = lambda_sim*repetitions;
+
+fprintf('Running %s.m: SimStack Minimal Example\n',mfilename)
+fprintf(['Simulated repetition length: %g nm\nSb2Te3-content eta: %g\n'...
+    'Total thickness: %g nm\n'],lambda_sim/10,eta_sim,t_sim/10)
+
+%% Sb2Te3 QT disordered structure simulation
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+% % calculate SL BiLayer Thickness
+lambda_sim = n_QL*t_QL + n_BL*t_BL;
+eta_sim = n_QL*3/n_BL;
+t_sim = lambda_sim*repetitions;
+c_GeTe=t_BL*3;
+c_Sb2Te3=t_QL*3;
+
+fprintf(['Simulated repetition length Lambda: %g nm\n', ...
+'Sample: %ix[%0.2f nm GeTe / %.2f nm Sb2Te3]', ...
+'eta n_QL*3/n_BL: %g\n',...
+'Total thickness: %g nm\n'],...
+lambda_sim/10,repetitions,n_BL*t_BL/10,n_QL*t_QL/10,eta_sim,t_sim/10)
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% generate randomized structures with the "buildStack" class
+tic
+fprintf('Generating %i structures with some randomness...\n', n_struct)
+for k=1:n_struct
+    n = repetitions;
+
+    stack = buildStack;
+    block_BL = stack.BL(c_GeTe);
+    block_QL = stack.QT_Kooi(c_Sb2Te3);
+
+    % build CSL structure
+    for i=1:n
+        % Sb2Te3 quintuples
+        n_QL_actual = -1;
+        while n_QL_actual < 0; n_QL_actual = n_QL+round((randn()*sqrt(s_QL))); end
+        stack.multiaddBlock(block_QL,n_QL_actual)
+        % GeTe bilayers
+        n_BL_actual = -1;
+        while n_BL_actual < 0; n_BL_actual = n_BL+round((randn()*sqrt(s_BL))); end
+        stack.multiaddBlock(block_BL,n_BL_actual)
+    end
+
+    % add top layer Sb2Te3
+    n_QL_actual = -1;
+    while n_QL_actual < 0; n_QL_actual = n_QL+round((randn()*sqrt(s_QL))); end
+    stack.multiaddBlock(block_QL,n_QL_actual)
+    stack.addAtom('Te',0.000);
+    stack_list{k} = stack;
+end
+toc
+% create SimStack object
+SimStackQTDisordered = SimStack('qz',Qz,'corr','LPTF');
+% add all the structures
+for k=1:n_struct
+    SimStackQTDisordered.addStructure(stack_list{k}.elements,stack_list{k}.zpos,stack_list{k}.z);
+end
+% calculate
+SimStackQTDisordered.update;
+% plot
+SimStackQTDisordered.plot;