Saddle point approaches in strong field physics and generation of attosecond pulses

Publication date: Available online 31 October 2019Source: Physics ReportsAuthor(s): Arjun Nayak, Mathieu Dumergue, Sergei Kühn, Sudipta Mondal, Tamás Csizmadia, N.G. Harshitha, Miklós Füle, Mousumi Upadhyay Kahaly, Balázs Farkas, Balázs Major, Viktor Szaszkó-Bogár, Péter Földi, Szilárd Majorosi, Nikolaos Tsatrafyllis, Emmanuel Skantzakis, Lana Neoričić, Mojtaba Shirozhan, Giulio Vampa, Katalin Varjú, Paraskevas TzallasAbstractAttoscience is the emerging field that accesses the fastest electronic processes occurring at the atomic and molecular length scales with attosecond (1 as = 10−18 s) time resolution having wide ranging physical, chemical, material science and biological applications. The quintessential and one of the most fundamental processes in this domain is the generation of phase locked XUV attosecond pulses. The theoretical approach to understand the process incorporates a fully quantum or semi classical or relativistic description of coherent charge dynamics in intense ultrashort electromagnetic fields driving a quantum system (an atom, a molecule, solid band gap materials or surface plasmas). Modelling of such physical and dynamical systems in science and also in many other branches often leads to equations represented in terms of complex multi-dimensional integrals. These integrals can often be solved using the stationary phase approximation, which leads to a series of equations identifying the points in the multi-dimensional space, having most s...
Source: Physics Reports - Category: Physics Source Type: research