Field-ionization threshold and its induced ionization-window phenomenon for Rydberg atoms in a short single-cycle pulse

Journal Article · Fri Dec 05 00:00:00 EST 2014 · Physical Review A - Atomic, Molecular, and Optical Physics

DOI:https://doi.org/10.1103/PhysRevA.90.063413· OSTI ID:2569821

Yang, B. C. ^[1]; Robicheaux, F. ^[1]

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1. Purdue University, West Lafayette, IN (United States)

We study the field-ionization threshold behavior when a Rydberg atom is ionized by a short single-cycle pulse field. Both hydrogen and sodium atoms are considered. The required threshold field amplitude is found to scale inversely with the binding energy when the pulse duration becomes shorter than the classical Rydberg period, and, thus, more weakly bound electrons require larger fields for ionization. This threshold scaling behavior is confirmed by both three-dimensional classical trajectory Monte Carlo simulations and numerically solving the time-dependent Schrödinger equation. More surprisingly, the same scaling behavior in the short pulse limit is also followed by the ionization thresholds for much lower bound states, including the hydrogen ground state. An empirical formula is obtained from a simple model, and the dominant ionization mechanism is identified as a nonzero spatial displacement of the electron. Here, this displacement ionization should be another important mechanism beyond the tunneling ionization and the multiphoton ionization. In addition, an “ionization window” is shown to exist for the ionization of Rydberg states, which may have potential applications to selectively modify and control the Rydberg-state population of atoms and molecules.

• Research Organization: Purdue University, West Lafayette, IN (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: SC0012193
• OSTI ID: 2569821
• Alternate ID(s): OSTI ID: 1179856
• Journal Information: Physical Review A - Atomic, Molecular, and Optical Physics, Journal Name: Physical Review A - Atomic, Molecular, and Optical Physics Journal Issue: 6 Vol. 90; ISSN 1094-1622; ISSN 1050-2947
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS