372
10 Time-Periodic Quantum Systems
Fig. 10.15 The 10% and
90% microwave ionization
threshold electric field
amplitude, E th (in V/cm), for
microwave frequency
f = 9.923 GHz and principal
quantum numbers n = 32 to
n = 90 (Koch 1988)
Fig. 10.16 Ionization curves
for principal quantum
numbers in the range n = 65
to n = 74 for microwave
frequency f = 9.923 GHz
(Koch 1988)
Additional experimental data can be found in Bayfield and Pinnaduwage (1985);
van Leeuwen et al. (1985); Bayfield and Sokol (1988); Galvez et al. (1988).
10.7.2 One-Dimensional Approximation
In the experiments described in Sect. 10.7.1, the hydrogen atoms are stretched into
highly excited elongated states with parabolic quantum numbers
(n; n 1 , n 2 , m) ≈ (n; 0, n − 1, 0)
and then driven by a microwave field. To first approximation, the hydrogen atoms
can be treated as one-dimensional objects, and much of their large-scale behavior
can be described by a one-dimensional approximation.