
April 25, 2014 11:1 PSP Book - 9in x 6in 06-Rashid-A.-Ganeev-c06
High-Order Harmonic Cutoff Frequency in Atomic Silver Irradiated 201
∫
ϕ
∗
n
(
r, t
)
p −
q
c
A
ϕ
m
(
r, t
)
dV =
∫
u
∗
n
(
r
)
pu
m
(
r
)
dV =
p
nm
.
(6.21)
By substituting the expansion (6.11) into (6.16) and applying Eq.
(6.17), we get the following equation for atomic current
J
(
t
)
=
q
m
n, m, p, q
a
∗
n
(
t
)
a
m
(
t
)
V
−1
np
(
t
)
p
pq
V
qm
(
t
)
. (6.22)
The most principle feature of Eqs. (6.20) and ( 6.21) is that the
right-hand side of these equations includes the matrix elements p
nm
,
which are calculated on the basis of the “free atom” eigenstates.
Notice that on the basis of the “free atom” eigenstates, the matrix
elements of momentum ...