Probing H_{2} Double Ionization with Bicircular Laser Fields.

We present a kinematically complete study on strong-field double ionization of H_{2} molecules in two-color bicircular laser fields. The releasing times of electrons and protons are recorded with the double-hand attoclock. We observe the relative emission angles of two electrons oscillate with the kinetic energy release of protons, indicating the internal concerted four-body fragmentation.

How has the field of metastatic breast cancer in bones evolved over the past 22 years?

Background: Although knowledge on metastatic breast cancer in bones (MBCB) has increased rapidly over the past 22 years, a comprehensive and objective bibliometric analysis is still lacking.

Materials And Methods: We used R, VOSviewer, and Citespace software to conduct a bibliometric analysis of 5,497 papers on MBCB from the Web of Science Core Collection (WOSCC) using author, institution, country/region, citation, and keyword indicators.

Results: A general strong sense of scholarly collaboration was noted in the MBCB field at the author, research institution, and country/region levels.

Probing the orbital angular momentum of intense vortex pulses with strong-field ionization.

With the rapid development of femtosecond lasers, the generation and application of optical vortices have been extended to the regime of intense-light-matter interaction. The characterization of the orbital angular momentum (OAM) of intense vortex pulses is very critical. Here, we propose and demonstrate a novel photoelectron-based scheme that can in situ distinguish the OAM of the focused intense femtosecond optical vortices without the modification of light helical phase.

Ultrafast imaging of spontaneous symmetry breaking in a photoionized molecular system.

The Jahn-Teller effect is an essential mechanism of spontaneous symmetry breaking in molecular and solid state systems, and has far-reaching consequences in many fields. Up to now, to directly image the onset of Jahn-Teller symmetry breaking remains unreached. Here we employ ultrafast ion-coincidence Coulomb explosion imaging with sub-10 fs resolution and unambiguously image the ultrafast dynamics of Jahn-Teller deformations of [Formula: see text] cation in symmetry space.

Probing the Spin-Orbit Time Delay of Multiphoton Ionization of Kr by Bicircular Fields.

We study multiphoton ionization of Kr atoms by circular 400-nm laser fields and probe its photoelectron circular dichroism with the weak corotating and counterrotating circular fields at 800 nm. The unusual momentum- and energy-resolved photoelectron circular dichroisms from the ^{2}P_{1/2} ionic state are observed as compared with those from ^{2}P_{3/2} ionic state. We identify an anomalous ionization enhancement at sidebands related to the ^{2}P_{1/2} ionic state on photoelectron momentum distribution when switching the relative helicity of the two fields from corotating to counterrotating.

Unifying Tunneling Pictures of Strong-Field Ionization with an Improved Attoclock.

We demonstrate a novel attoclock, in which we add a perturbative linearly polarized light field at 400 nm to calibrate the attoclock constructed by an intense circularly polarized field at 800 nm. This approach can be directly implemented to analyze the recent hot and controversial topics involving strong-field tunneling ionization. The generally accepted picture is that tunneling ionization is instantaneous and that the tunneling probability synchronizes with the laser electric field.