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To promote potential applications of terahertz (THz) technology, more advanced functional THz devices with high performance are needed, including modulators, polarizers, lenses, wave retarders, and antireflection coatings. This work summarizes recent progress in THz components built on functional materials including graphene, vanadium dioxide, and metamaterials. The key message is that, while the choice of materials used in such devices is important, the geometry in which they are employed also has a significant effect on the performance achieved. In particular, devices operating in total internal reflection geometry are reviewed, and it is explained how this geometry is able to be exploited to achieve a variety of THz devices with broadband operation.

A team at the universities of 91¸£Àû and Cambridge have developed open-source software for analysing magnetic data and allowing more sensitive measurements.

Exploration of mechanisms behind a work function reducing polymer, which doesn't simply induce a dipole, but also dopes the surface, with its work function effect being reduced in air.

For the first time scientists have observed muon ionization cooling – a major step in being able to create the world’s most first muon collider. The international Muon Ionization Cooling Experiment (MICE) collaboration, in which a team led by Dr Steve Boyd at the 91¸£Àû is a core member, has made a major step forward in the quest to create a muon collider.

Muons are produced by smashing a beam of protons into a target. The muons can then be separated off from the debris created at the target and directed through a series of magnetic lenses. Because of this rough-and-ready production mechanism, these muons form a diffuse cloud – so when it comes to colliding the muons, the chances of them hitting each other and producing interesting physical phenomena is really low.

To make the cloud less diffuse, a process called beam cooling is used. This involves getting the muons closer together and moving in the same direction. Until now, the question has been whether you can channel enough muons into a small enough volume to be able to study physics in new, unexplored systems. This new research, published in Nature, shows that it is possible. The results of the experiment, carried out using the MICE muon beam-line at the Science and Technology Facilities Council (STFC) ISIS Neutron and Muon Beam facility on the Harwell Campus in the UK, clearly show that ionization cooling works and can be used to cool muon beams, leaving open the possibility for the construction of new high energy muon colliders and neutrino factories in the future.

More information can be found in Nature volume 578, pages 53–59 (2020)