The perceived dichotomy between analytical and ab initio approaches to theory in
attosecond science is often seen as a source of tension and misconceptions. This Topical …

Single ionization of He by two oppositely circularly polarized, time-delayed attosecond
pulses is shown to produce photoelectron momentum distributions in the polarization plane …

Multistart spiral vortex patterns are predicted for the electron momentum distributions in the
polarization plane following ionization of the helium atom by two time-delayed circularly …

We describe an ab initio and nonperturbative R-matrix with time-dependence theory for
ultrafast atomic processes in light fields of arbitrary polarization. The theory is applicable to …

Photoionization through single-photon absorption by two synchronous, linearly chirped,
oppositely circularly polarized, attosecond pulses is known [NJ Strandquist, Jr., and JM …

Electron correlation plays an essential role in a wide range of fundamentally important many-
body phenomena in modern physics and chemistry. An example is the importance of …

Two-armed helical vortex structures are predicted in the two-electron momentum
distributions produced in double photoionization (DPI) of the He atom by a pair of time …

A class of linear, spiral phenomena is discovered in the photoelectron momentum
distribution when studying photoionization of S-state atoms by a pair of linearly chirped …

The photoelectron momentum distribution (PMD) for the linear (in intensity) process of one-
photon single ionization of carbon monoxide is examined in the polarization plane for …

During the past five decades, classical dynamics have been systematically used to gain
insight on collision processes between charged particles and photons with atomic and …