INTERFERENCES IN THE ATTOSECOND PHOTOELECTRON SPECTRA OF H2+ AND HeH2+ MOLECULES

BOLL, DIEGO IVÁN RENÉ; FOJÓN, OMAR ARIEL

Dublin

Simposio; International Symposium on (e,2e), Double Photo-ionization & Related Topics & 16th International Symposium on Polarization & Correlation in Electronic & Atomic Collisions; 2011

We study theoretically interferences in the photoelectron spectra resulting from laser assisted x-ray photoionization in the framework of a sudden approximation model [1]. In this approach, the evolution of the system is splitted up in three time intervals and the Coulomb-Volkov wavefunction is exploited to obtain a non relativistic quantum theory of attosecond photoionization in the presence of a laser field. The obtention of the observables of the reaction, i.e., the Multiple Differential Cross Sections (MDCS) corresponding to the laser assisted photoelectron spectrum is reduced to the knowledge of Monochromatic Photoionization Amplitudes (MPA) [1]. We analyze the case of simple monoelectronic diatomic molecules such as H2+ and HeH 2+. We present MDCS obtained in two different ways: i) by means of MPA computed through a two-center approximation [2] and ii) by using precise monochromatic photoionization cross sections [3]. In the latter, a realistic description of the molecular nature of the problem is achieved by using B-splines techniques [4,5]. We consider the application of a single ultrashort pulse as well as two pulse replicas and we analyze the presence of several interference patterns in the photoelectron spectra. References. [1]. G.L. Yudin et al, J. Phys. B: At. Mol. Opt. Phys. (2007) 40 F93. [2]. G.L. Yudin, S. Chelkowski and A. Bandrauk, J. Phys. B: At. Mol. Opt. Phys. (2006) 39 L17. [3]. O. Fojón, A. Palacios, J. Fernández, R. Rivarola and F. Martín, Phys. Lett. A (2006) 350 371. [4]. F. Martín, J. Phys. B (1999) 32 R197. [5]. I. Sánchez and F. Martín, J. Phys. B: At. Mol. Opt. Phys. (1997) 30 679.