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Image published in O. El Gawhary, T. Van Mechelen, and H. P. Urbach: Role of Radial Charges on the Angular Momentum of Electromagnetic Fields: Spin-3/2 Light, Physical Review Letters Vol. 121, DOI:https://doi.org/10.1103/PhysRevLett.121.123202

Research on thin films to be published in the peer-reviewed journal Physical Review Letters

A paper describing work within current EMPIR project 'Hybrid metrology for thin films in energy applications' (16ENG03 Hymet) and recently completed project 'Metrology for highly-parallel manufacturing' (14IND09 MetHPM) has been accepted for the prestigious journal of the American Physics Society Physical Review Letters.

The research carried out in these projects will develop new capabilities to assess thin film performance to aid their deployment in novel energy applications.

The science described in the paper is complex, and has kept researchers busy for decades while investigating novel ways to extract information from light-matter.

In the work the role of a recently discovered new topological radial charge carried by electromagnetic fields is discussed and its role on the Total Angular Momentum of electromagnetic fields. What is found is that that radial charge is responsible for the coupling between the spin and orbital angular momentum.

Fields with a spin-3/2 were also found, where spin is a form of angular momentum carried by elementary particles or fields. This is a ground breaking discovery, very interesting for the scientists working on the electromagnetic fields, and counterintuitive to what they were expecting. This is because photons are known to carry spin-1.

This finding contributes to our understanding of the physics and angular momentum of electromagnetic fields, which has many diverse energy applications.

The paper Role of Radial Charges on the Angular Momentum of Electromagnetic Fields: Spin-3/2 Light >>

These EMPIR projects are co-funded by the European Union's Horizon 2020 research and innovation programme and the EMPIR Participating States