When a magnetic material is bombarded with short pulses of laser light, it loses its magnetism within femtoseconds (10 –15 seconds). The spin, or angular momentum, of the electrons in the material ...

In an introductory physics course, there are three big ideas. There is the work-energy principle, the momentum principle and then the angular momentum principle. I'll skip the work-energy principle ...

A research team succeeds in solving a decade-old physical puzzle: the question of the fate of angular momentum during the ultrafast demagnetization of nickel crystals by laser light. In a closed ...

Introduction You might have seen figure skaters spinning around quickly and then tucking their arms to spin faster—or opening them to spin more slowly. This happens, thanks to a physics concept known ...

Photons can have half-integer values of angular momentum when they are confined to fewer than three dimensions. That is the conclusion of physicists in Ireland, who have revived an experiment first ...

Ultrashort measurement-time resolution is traditionally obtained in pump–probe experiments, for which two ultrashort light pulses are required; the time resolution is then determined by the pulse ...

Optical vortices are currently one of the most intensively studied topics in optics. These light beams, which carry orbital angular momentum (OAM), have been successfully utilized in the visible and ...

Publications of the Astronomical Society of the Pacific, Vol. 131, No. 995 (2019 January), pp. 1-8 (8 pages) To understand the distribution of angular momenta between host stars and their planets, we ...