Portal de Periódicos da CAPES

Laser Phase Control of High-Order Harmonic Generation at Large Internuclear Distance: The H + − H 2 + System

2007; American Physical Society; Volume: 98; Issue: 1 Linguagem: Inglês

10.1103/physrevlett.98.013001

1092-0145

André D. Bandrauk, Samira Barmaki, G. Lagmago Kamta,

Mass Spectrometry Techniques and Applications

Exact (Born-Oppenheimer) 3-D numerical solutions of the time-dependent Schrödinger equation are obtained for the one electron linear H+-H2+ atom-molecule system at large internuclear distance R in interaction with two-cycles intense (I>10(14) W cm(-2)) 800 nm laser pulses. High-order harmonic generation (HHG) spectra are obtained with an energy cutoff larger than the atomic maximum of I(p)+3U(p), where I(p) is the ionization potential and U(p) is the ponderomotive energy. At large R, this extended cutoff is shown to be related to the nature of electron transfer, whose direction is shown to depend critically on the carrier-envelope phase (CEP) of the ultrashort pulse. Constructive and destructive interferences in the HHG spectrum resulting from coherent superpositions of electronic states in the H+-H2+ system are interpreted in terms of multiple electron trajectories extracted from a time profile analysis.