ξ+
0.0
1.0
2.0
3.0
4.0
5.0
-0.3
-0.2
-0.1
0.0
0.1
0.2
0.3
Re(ξ+)
Im(ξ+)

x/a

 
eikx
0.0
1.0
2.0
3.0
4.0
5.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
Re(eikx)
Im(eikx)

x/a

 
uk
0.0
1.0
2.0
3.0
4.0
5.0
-0.20
-0.10
0.00
0.10
0.20
0.30
Re(uk)
Im(uk)

x/a

  

a:

 [m]

b:

 [m]

c1:

 [m/s]

c2:

 [m/s]

ω:

 [rad/s]

Fig. 4. The eigenfunctionss can be written in Bloch form ξ+ = eikxuk(x) where uk(x) = uk(x + a) is a periodic function. Source file.