Topology has played a central role in modern physics. New phases of matter and phase transitions (1, 2), as well as electronic band theory (3), are understood in terms of topological concepts. On page 1449 of this issue, Tai and Smalyukh (4) harness topology to create a fundamentally new type of crystal, built with knots tied in a chiral fluid (see the figure). They used a liquid crystal doped with a chiral molecule, which caused all of the molecules to rotate like a corkscrew along a preferred direction, the helical axis. Using electric fields, they created vortex lines in the helical axis and tied them into knots that act like “atoms” but on the micrometer scale. Different knotted particles were created by careful illumination with laser tweezers, and their interactions were tuned so that they spontaneously assembled into two- or three-dimensional lattices.
Gareth Alexander's paper appears in Science, Vol. 365, Issue 6460, pp. 1377
The LHCb collaboration has, this week, published long-awaited results on matter-antimatter asymmetries in B+ → π+π+π− decays, explaining the curious variation of the asymmetry across the phase space.
Professor Sandra Chapman is part of the Centre for Fusion, Space and Astrophysics in the Physics Department and is taking part in the British Science Festival happening on campus in September.
Click for a short video featuring Sandra explaining her research, and details of the event at the British Science Festival.
Assistant Professor and Royal Society Dorthy Hodgkin Fellow in the Astronomy and Astrophysics group Farzana Meru researches planet formation, planet evolution and disc evolution. She is taking part in the British Science Festival happening on campus in September.
Click for a short video explaining some of Farzana's research, and details of her event at the British Science Festival.
First-ever visualisations of electrical gating effects on electronic structure could lead to longer-lasting devices
A team including Neil Wilson and Nick Hine has visualised the electronic structure in a microelectronic device for the first time, opening up opportunities for finely-tuned high-performance electronic devices.
Physicists from the University of Warwick and the University of Washington have developed a technique to measure the energy and momentum of electrons in operating microelectronic devices made of atomically thin, so-called two-dimensional, materials.
Using this information, they can create visual representations of the electrical and optical properties of the materials to guide engineers in maximising their potential in electronic components.
The experimentally-led study is published in Nature and could also help pave the way for the two-dimensional semiconductors that are likely to play a role in the next generation of electronics, in applications such as photovoltaics, mobile devices and quantum computers.
The Warwick Photoemission Facility and the Departments of Chemistry & Physics have recently contributed to a study to "upconvert" cellulosic waste in an effort to develop new carbon-neutral biofuels.