El acceso a la versión del editor puede requerir la suscripción del recurso Access to the published version may require subscription Ultrafast Electron Dynamics in Phenylalanine Initiated by Attosecond Pulses Abstract:In the last decade attosecond technology has opened up the investigation of ultrafast electronic processes in atoms, simple molecules and solids. Here we report the application of isolated attosecond pulses to prompt ionization of the amino acid phenylalanine, and the subsequent detection of ultrafast dynamics on a sub-4.5-fs temporal scale, which is shorter than the vibrational response of the molecule. The ability to initiate and observe such electronic dynamics in polyatomic molecules represents a crucial step forward in attosecond science, which is progressively moving towards the investigation of more and more complex systems.One Sentence Summary: Ultrafast electron dynamics on a sub-4.5-fs temporal scale, which precedes any nuclear motion, is initiated in an amino acid by attosecond pulses.

One of the most significant developments in computational atomic and molecular physics in recent years has been the introduction of B-spline basis sets in calculations of atomic and molecular structure and dynamics. B-splines were introduced in applied mathematics more than 50 years ago, but it has been in the 1990s, with the advent of powerful computers, that the number of applications has grown exponentially. In this review we present the main properties of B-splines and discuss why they are useful to solve different problems in atomic and molecular physics. We provide an extensive reference list of theoretical works that have made use of B-spline basis sets up to 2000. Among these, we have focused on those applications that have led to the discovery of new interesting phenomena and pointed out the reasons behind the success of the approach.

Esta es la versión de autor del artículo publicado en: This is an author produced version of a paper published in: The extraordinary success of graphene and its tremendous potential applications [1] paved the way for the rising of a completely new family of two dimensional materials. [2] Graphene is a semimetal with zero-gap, which limits its use in the electronics technology. Transition metal dichalcogenides present a band gap in the range of 1.5 -2.5 eV [3] (depending on the thickness, strain level and chemical composition), which makes them inappropriate for some optoelectronics applications where band gaps in the 0.1 -1 eV range are commonly preferred. [4] Black phosphorous (BP), [5] a layered allotrope of phosphorous, presents an energy gap in this range and hence it is now intensely studied to better understand its electronics properties in the few-layer conformation. However, it shows a relatively large reactivity. Exfoliated flakes of BP are highly hygroscopic and tend to uptake moisture from

Esta es la versión de autor del artículo publicado en: This is an author produced version of a paper published in:Science 354(6313) (2016): 734-738 DOI: http://dx.doi.org/10.1126/science.aah5188 Copyright: © 2016 American Association for the Advancement of ScienceEl acceso a la versión del editor puede requerir la suscripción del recurso Access to the published version may require subscription However, the rapidity of electron dynamics on the attosecond timescale has precluded their complete measurement in the time domain. Here, we demonstrate that spectrally-resolved electron interferometry reveals the amplitude and phase of a photoelectron wavepacket created through a Fano autoionizing resonance in helium. Replicas obtained by two-photon transitions interfere with reference wavepackets formed through smooth continua, allowing the full temporal reconstruction, purely from experimental data, of the resonant wavepacket released in the continuum. This in turn resolves the buildup of the autoionizing resonance on attosecond timescale. Our results, in excellent agreement with ab initio time-dependent calculations, raise prospects for both detailed investigations of ultrafast photoemission dynamics governed by electron correlation, as well as coherent control over structured electron wave-packets.One Sentence Summary: By monitoring the decay of an excited atom in real time, we reconstruct how photoelectron wavepackets are born and morph into asymmetric Fano profiles. Main Text:Tracking electronic dynamics on the attosecond (as) timescale and Ångström (Å) lengthscale is a key to understanding and controlling the quantum mechanical underpinnings of physical and chemical transformations (1). One of the most fundamental electronic processes in this context is photoelectron emission, the dynamics of which are fully encoded in the released electron wavepacket (EWP) and the final ionic state. The development of broadband coherent sources of attosecond pulses has opened the possibility of investigating these dynamics with attosecond resolution. On such a short timescale, few techniques (2-5) are able to provide access to both spectral amplitude and phase. The spectral derivative of the phase, the group delay, is a practical quantity for describing general wavepacket properties reflecting the ionization dynamics.