WOLFRAM
|
DEMONSTRATIONS PROJECT
Band Spectrum in a Periodic Potential
ε
P
l
o
t
o
f
t
h
e
s
y
m
m
e
t
r
i
c
s
o
l
u
t
i
o
n
o
f
-
ψ
'
'
(
x
)
+
c
o
s
(
x
)
ψ
(
x
)
=
ϵ
ψ
(
x
)
.