Time-dependent density functional theory: Past, present, and future

Time-dependent density functional theory (TDDFT) is presently enjoying enormous popularity in quantum chemistry, as a useful tool for extracting electronic excited state energies. This article discusses how TDDFT is much broader in scope, and yields predictions for many more properties. We discuss some of the challenges involved in making accurate predictions for these properties.Comment: 12 pages, 4 figure

Multiphoton radiative recombination of electron assisted by laser field

In the presence of an intensive laser field the radiative recombination of the continuum electron into an atomic bound state generally is accompanied by absorption or emission of several laser quanta. The spectrum of emitted photons represents an equidistant pattern with the spacing equal to the laser frequency. The distribution of intensities in this spectrum is studied employing the Keldysh-type approximation, i.e. neglecting interaction of the impact electron with the atomic core in the initial continuum state. Within the adiabatic approximation the scale of emitted photon frequencies is subdivided into classically allowed and classically forbidden domains. The highest intensities correspond to emission frequencies close to the edges of classically allowed domain. The total cross section of electron recombination summed over all emitted photon channels exhibits negligible dependence on the laser field intensity.Comment: 14 pages, 5 figures (Figs.2-5 have "a" and "b" parts), Phys.Rev.A accepted for publication. Fig.2b is presented correctl

Isolated Attosecond Pulses from Laser-Driven Synchrotron Radiation

A quantitative theory of attosecond pulse generation in relativistically driven overdense plasma slabs is presented based on an explicit analysis of synchrotron-type electron trajectories. The subcycle, fieldcontrolled release, and subsequent nanometer-scale acceleration of relativistic electron bunches under the combined action of the laser and ionic potentials give rise to coherent radiation with a high-frequency cutoff, intensity, and radiation pattern explained in terms of the basic laws of synchrotron radiation. The emerging radiation is confined to time intervals much shorter than the half-cycle of the driver field. This intuitive approach will be instrumental in analyzing and optimizing few-cycle-laser-driven relativistic sources of intense isolated extreme ultraviolet and x-ray pulses