Catálogo de publicaciones - revistas

<jats:p> <jats:italic>Frequencies of frequency standards are shifted by the local static gravity red shifts and also modulated by the tidal relativistic red shifts. We compute the tidal relativistic red shifts using a time-domain method and present the numerical results for the National Institute of Metrology (NIM) in Beijing, Laboratoire National de Métrologie et Essais-Systéme de Références Temps-Espace (LNE-SYRTE) in Paris and Physikalisch-Technische Bundesanstalt (PTB) in Braunschweig. The differences of the tidal relativistic red shift approach as large as</jats:italic> 1.1×10<jats:sup>−16</jats:sup> <jats:italic>when frequency standards at NIM are compared with those at SYRTE and PTB. Moreover, the tidal relativistic red shifts of frequency standards in space stations are also computed</jats:italic>.</jats:p>

<jats:p> <jats:italic>We investigate the above-threshold ionization of an atom in a combined infrared (IR) and extreme ultraviolet (XUV) two-color laser field and focus on the role of XUV field in the high-order above-threshold ionization (HATI) process. It is demonstrated that, in stark contrast to previous studies, the XUV laser may play a significant role in atomic HATI process, and in particular, the XUV laser can accelerate the ionized electron in a quantized way during the collision between the electron and its parent ion. This process cannot be explained by the classical three-step model. Our results indicate that the previously well-established concept that HATI is an elastic recollision process is broken down</jats:italic>.</jats:p>