clc clear all close all a_cc=1.42; etha=0.00001; N=2; t=2.7; m=sqrt(3); b=(m*a_cc)/2; a=(3*a_cc)/2; %%%%%%%%%%%%%%%%%%%%%%%%%% EE=[]; for kx=-pi/a:0.1:pi/a; for ky=-2*pi/3*b:0.1:2*pi/3*b; h_0=-t*(1+2*(exp(1i*kx*a)*cos(ky*b))); H_k=zeros(N); H_k(1,2)=h_0; H_k(2,1)=(H_k(1,2))'; E=eig(H_k); EE=[EE,E]; end end %%%%%%%%%%%%%%%%%%%%%%%%%%%%%% [kx,ky]=meshgrid(-pi/a:0.1:pi/a,-2*pi/3*b:0.1:2*pi/3*b); mesh(kx,ky,E) zlabel('Energy(eV)') ylabel('kx') xlabel('ky'); % axis([-4 4 -4 4 -5 4])