Category Physics

Excitation spectra of the Higgs mode

Researchers produce a state in which atoms behave similarly to a Higgs boson. Physicists at the University of Bonn have succeeded in putting a superconducting gas into an exotic state. Their experiments allow new insights into the properties of the Higgs particle, but also into fundamental characteristics of superconductors.

For their experiments, scientists at the University of Bonn used a gas made of lithium atoms, which they cooled down significantly. At a certain temperature, the state of the gas changes abruptly: It becomes a superconductor that conducts a current without any resistance. Physicists also speak of a phase transition. A similar sudden change occurs with water when it freezes.

The lithium gas changes to a more orderly state at its phas...

Range of the size for a typical neutron star compared to the city of Frankfurt. Credit: Lukas Weih, Goethe University, satellite image: GeoBasis-DE/BKG (2009) Google

Comparison of billions of theoretical models with gravitational waves results in the answer to an old riddle. How large is a neutron star? Previous estimates varied from eight to sixteen kilometres. Astrophysicists at the Goethe University Frankfurt and the FIAS have now succeeded in determining the size of neutron stars to within 1.5 kilometres by using an elaborate statistical approach supported by data from the measurement of gravitational waves. The researchers’ report appears in the current issue of Physical Review Letters.

Neutron stars are the densest objects in our universe, with a mass larger than that of our sun comp...

Sandia National Laboratories postdoctoral appointee Polina Vabishchevich, left, and Senior Scientist Igal Brener made a metamaterial that mixes two lasers to produce 11 colors ranging from the near infrared, through the colors of the rainbow, to ultraviolet. Credit: Photo by Randy Montoya

First nanostructured material for broad mixing of light waves. A multicolor laser pointer you can use to change the color of the laser with a button click – similar to a multicolor ballpoint pen – is one step closer to reality thanks to a new tiny synthetic material made at Sandia National Laboratories...

a) This is a photograph of the spherical colloidal crystals containing 0.20 wt% carbon black (CB). The size of the fine silica particles ranges from 200 to 300 nm, and 11 different sizes were used. b) This is a picture of a weevil drawn using spherical colloidal crystals prepared using monodispersed silica particles with various particle sizes and CB. The surroundings of the weevils are drawn with spherical colloidal crystals that do not contain CB and change with the color of the background. Credit: John Wiley & Sons, Inc.

Researchers at Nagoya University develop a composite material that, by adjusting its composition and exposing it to different types of light, can mimic animals’ changes in color...