Inherent contradictions in the tunneling-multiphoton dichotomy

Journal Article · Thu Mar 15 00:00:00 EDT 2007 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.75.031404· OSTI ID:20982222

Reiss, H R ^[1]

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1. Max Born Institute, 12489 Berlin, Germany and American University, Washington, DC 20016-8058 (United States)

Strong-field phenomena are currently described as being multiphoton or tunneling, based on whether the Keldysh parameter {gamma} is greater than or less than unity. There are disqualifying features in this categorization. It is specific to the length gauge, dependent on only one intensity parameter, and backward in the sense that ionization with {gamma}>>1 can occur only by tunneling, and ionization with {gamma}<<1 must be over the barrier, and hence is not achieved by tunneling. As {gamma} becomes smaller, ionization becomes increasingly distant from tunneling, and eventually reaches conditions where the dipole approximation fails and there is no meaningful scalar-potential diagram at all.

• OSTI ID: 20982222
• Journal Information: Physical Review. A, Vol. 75, Issue 3; Other Information: DOI: 10.1103/PhysRevA.75.031404; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
APPROXIMATIONS
DIPOLES
MULTI-PHOTON PROCESSES
PHOTOIONIZATION
PHOTON-ATOM COLLISIONS
POTENTIALS
STRONG INTERACTIONS
TUNNEL EFFECT