interface-state-project-matlab-codes/bandstructure.m at master · minspan199/interface-state-project-matlab-codes · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
clear all;

ksA = 0;
t1 = 0.5;t2 = 1;
k = 1;


r = 0;
for kb = -pi:0.05:pi
    H = [1i*r t1 + t2*exp(-1i*kb);t1 + t2*exp(1i*kb) -1i*r];
    tem{k} = eig(H);
    ksp(k) = tem{k}(1);
    ksm(k) = tem{k}(2);
    k = k+1;
end

figure
subplot(1,3,1)
plot(-pi:0.05:pi,real(ksp),'b.');hold on;
plot(-pi:0.05:pi,imag(ksp),'r.');
plot(-pi:0.05:pi,real(ksm),'b.');
plot(-pi:0.05:pi,imag(ksm),'r.');
set(gca,'xtick',[-pi,-pi/2,0,pi/2,pi]);
set(gca,'xticklabel',{'-\pi','-\pi/2','0','\pi/2','\pi'});
set(gca,'Fontname','Times New Roman')
set(gcf, 'Position', [00, 00, 250, 200])
set(gca,'Fontsize',10)
% legend('Re[\epsilon]','Im[\epsilon]')
xlim([-pi pi]);ylim([-2 2])


r = 1.25;k = 1;
for kb = -pi:0.05:pi
    H = [1i*r t1 + t2*exp(-1i*kb);t1 + t2*exp(1i*kb) -1i*r];
    tem{k} = eig(H);
    ksp(k) = tem{k}(1);
    ksm(k) = tem{k}(2);
    k = k+1;
end

subplot(1,3,2)
plot(-pi:0.05:pi,real(ksp),'b.');hold on;
plot(-pi:0.05:pi,imag(ksp),'r.');
plot(-pi:0.05:pi,real(ksm),'b.');
plot(-pi:0.05:pi,imag(ksm),'r.');
set(gca,'xtick',[-pi,-pi/2,0,pi/2,pi]);
set(gca,'xticklabel',{'-\pi','-\pi/2','0','\pi/2','\pi'});
set(gca,'Fontname','Times New Roman')
set(gcf, 'Position', [00, 00, 250, 200])
set(gca,'Fontsize',10)
% legend('Re[\epsilon]','Im[\epsilon]')
xlim([-pi pi]);ylim([-2 2])

r = 1.75;k = 1;
for kb = -pi:0.05:pi
    H = [1i*r t1 + t2*exp(-1i*kb);t1 + t2*exp(1i*kb) -1i*r];
    tem{k} = eig(H);
    ksp(k) = tem{k}(1);
    ksm(k) = tem{k}(2);
    k = k+1;
end

subplot(1,3,3)
plot(-pi:0.05:pi,real(ksp),'b.');hold on;
plot(-pi:0.05:pi,imag(ksp),'r.');
plot(-pi:0.05:pi,real(ksm),'b.');
plot(-pi:0.05:pi,imag(ksm),'r.');
set(gca,'xtick',[-pi,-pi/2,0,pi/2,pi]);
set(gca,'xticklabel',{'-\pi','-\pi/2','0','\pi/2','\pi'});
set(gca,'Fontname','Times New Roman')
set(gcf, 'Position', [00, 00, 500, 150])
set(gca,'Fontsize',10)
% legend('Re[\epsilon]','Im[\epsilon]')
xlim([-pi pi]);ylim([-2 2])