diff --git a/academic_codes/2020.06.26_Hamiltonian_and_bands_of_Kane_Mele_model_without considering_Rashba_SOC/Kane_Mele_model.m b/academic_codes/2020.06.26_Hamiltonian_and_bands_of_Kane_Mele_model_without considering_Rashba_SOC/Kane_Mele_model.m
new file mode 100644
index 0000000..dc5d569
--- /dev/null
+++ b/academic_codes/2020.06.26_Hamiltonian_and_bands_of_Kane_Mele_model_without considering_Rashba_SOC/Kane_Mele_model.m	
@@ -0,0 +1,101 @@
+% Purpose: Plot Kane-Mele's bands
+% Date: Dec 07, 2021 @HNU
+% Author: Ji-Huan Guan; 
+% Modify by Zhong-Fu Li;
+% More code can be found in https://www.guanjihuan.com/
+
+close all
+clc
+clear all
+tic;
+
+k0 = linspace(0,2*pi,100);
+for kk = 1:100
+    k = k0(kk);
+    H1 = HH(k);
+    [VV,DD] = eig(H1);
+    Ds(:,kk) = sort(diag(DD),'ascend'); % sort eigenvalue
+end
+plot(k0/2/pi,Ds,'k.');
+ylim([-1 1])
+set(gca,'xtick',[0:0.5:1])
+set(gca,'XTickLabel',{'\bf 0','\bf \pi','\bf 2\pi'})
+set(gcf,'color','w');
+set(gca,'fontsize',16,'LineWidth',1.1);
+ylabel('Energy(a.u.)','fontname','Arial');
+toc
+
+% define Hamiltonian
+function H = HH(k)
+N = 10;
+M = 0;
+t1 = 1;
+t2 = 0.03;
+phi = pi/2;
+h00 = zeros(2 * 4 * N, 2 * 4 * N);
+h01 = zeros(2 * 4 * N, 2 * 4 * N);
+for spin = 1:2
+    for ii = 0:N-1
+        % nearest neighbor couplings
+        h00(ii * 4 * 2 + 0 * 2 + spin, ii * 4 * 2 + 1 * 2 + spin) = t1;
+        h00(ii * 4 * 2 + 1 * 2 + spin, ii * 4 * 2 + 0 * 2 + spin) = t1;
+        
+        h00(ii * 4 * 2 + 1 * 2 + spin, ii * 4 * 2 + 2 * 2 + spin) = t1;
+        h00(ii * 4 * 2 + 2 * 2 + spin, ii * 4 * 2 + 1 * 2 + spin) = t1;
+        
+        h00(ii * 4 * 2 + 2 * 2 + spin, ii * 4 * 2 + 3 * 2 + spin) = t1;
+        h00(ii * 4 * 2 + 3 * 2 + spin, ii * 4 * 2 + 2 * 2 + spin) = t1;
+        %next nearest neighbor couplings
+        h00(ii * 4 * 2 + 0 * 2 + spin, ii * 4 * 2 + 2 * 2 + spin) = t2 * exp(-1j * phi) * sign_spin(spin);
+        h00(ii * 4 * 2 + 2 * 2 + spin, ii * 4 * 2 + 0 * 2 + spin) = conj(h00(...
+            ii * 4 * 2 + 0 * 2 + spin, ii * 4 * 2 + 2 * 2 + spin));
+        h00(ii * 4 * 2 + 1 * 2 + spin, ii * 4 * 2 + 3 * 2 + spin) = t2 * exp(-1j * phi) * sign_spin(spin);
+        h00(ii * 4 * 2 + 3 * 2 + spin, ii * 4 * 2 + 1 * 2 + spin) = conj(h00(...
+            ii * 4 * 2 + 1 * 2 + spin, ii * 4 * 2 + 3 * 2 + spin));
+        %
+    end
+    for ii = 0:N-2
+        % nearest neighbor couplings
+        h00(ii * 4 * 2 + 3 * 2 + spin, (ii + 1) * 4 * 2 + 0 * 2 + spin) = t1;
+        h00((ii + 1) * 4 * 2 + 0 * 2 + spin, ii * 4 * 2 + 3 * 2 + spin) = t1;
+        
+        % next nearest neighbor couplings
+        h00(ii * 4 * 2 + 2 * 2 + spin, (ii + 1) * 4 * 2 + 0 * 2 + spin) = t2 *exp(1j * phi) * sign_spin(spin);
+        h00((ii + 1) * 4 * 2 + 0 * 2 + spin, ii * 4 * 2 + 2 * 2 + spin) = conj(h00(...
+            ii * 4 * 2 + 2 * 2 + spin, (ii + 1) * 4 * 2 + 0 * 2 + spin));
+        h00(ii * 4 * 2 + 3 * 2 + spin, (ii + 1) * 4 * 2 + 1 * 2 + spin) = t2 * exp(1j * phi) * sign_spin(spin);
+        h00((ii + 1) * 4 * 2 + 1 * 2 + spin, ii * 4 * 2 + 3 * 2 + spin) = conj(h00(...
+            ii * 4 * 2 + 3 * 2 + spin, (ii + 1) * 4 * 2 + 1 * 2 + spin) );
+    end
+    % hopping of intercell h01
+    for ii = 0:N-1
+        % nearest neighbor couplings
+        h01(ii * 4 * 2 + 1 * 2 + spin, ii * 4 * 2 + 0 * 2 + spin) = t1;
+        h01(ii * 4 * 2 + 2 * 2 + spin, ii * 4 * 2 + 3 * 2 + spin) = t1;
+        
+        % next nearest neighbor couplings
+        h01(ii * 4 * 2 + 0 * 2 + spin, ii * 4 * 2 + 0 * 2 + spin) = t2 * exp(1j * phi) * sign_spin(spin);
+        h01(ii * 4 * 2 + 1 * 2 + spin, ii* 4 * 2 + 1 * 2 + spin) = t2 * exp(-1j * phi) * sign_spin(spin);
+        h01(ii * 4 * 2 + 2 * 2 + spin, ii * 4 * 2 + 2 * 2 + spin) = t2 * exp(1j * phi) * sign_spin(spin);
+        h01(ii * 4 * 2 + 3 * 2 + spin, ii * 4 * 2 + 3 * 2 + spin) = t2 * exp(-1j * phi) * sign_spin(spin);
+        
+        h01(ii * 4 * 2 + 1 * 2 + spin, ii * 4 * 2 + 3 * 2 + spin) = t2 * exp(1j * phi) * sign_spin(spin);
+        h01(ii * 4 * 2 + 2 * 2 + spin, ii * 4 * 2 + 0 * 2 + spin) = t2 * exp(-1j * phi) * sign_spin(spin);
+        if ii ~= 0
+            h01(ii * 4 * 2 + 1 * 2 + spin, (ii - 1) * 4 * 2 + 3 * 2 + spin) = t2 * exp(1j * phi) * sign_spin(spin);
+        end
+    end
+   for ii = 0:N-2
+    h01(ii * 4 * 2 + 2 * 2 + spin, (ii + 1) * 4 * 2 + 0 * 2 + spin) = t2 *exp(-1j * phi) * sign_spin(spin);
+   end
+end
+H = h00 + h01 * exp(1j * k) + h01' * exp(-1j * k);
+end
+
+function sign = sign_spin(spin)
+if spin == 0
+    sign = 1;
+else
+    sign = -1;
+end
+end
\ No newline at end of file