Laser smashes light-speed record
Special relativity prevents any object with mass travelling at the speed of light, and the principle of causality – the notion that the cause comes before the effect – is used to rule out ...
Superconducting gains
The device has three electrodes: a niobium injector electrode; a common electrode that consists of a layer of niobium and a layer of aluminium; and a niobium detector electrode. The electrodes are sep...
Nuclei show their soft side
Helium-6 is a typical neutron-skin nucleus, with two of the neutrons forming a “skin” around the alpha-particle core. Different types of dynamics are possible in such nuclei. In the soft d...
Laser control of X-ray output
In harmonic generation a short pulse of intense radiation is focussed into a gas of atoms. The laser-atom interactions are highly nonlinear, and a number of the input photons effectively combine to ge...
Schrodinger’s cat comes into view
In his original thought experiment, Schrodinger imagined that a cat is locked in a box, along with a radioactive atom that is connected to a vial containing a deadly poison. If the atom decays, it cau...
Theory, experiment and fine structure
Spectroscopy – the measurement of the properties of light emitted or absorbed by matter – is one of our most powerful tools to study nature. When a prism is used to separate the light from...
Closing in on gamma-ray bursts
The origin of gamma-ray bursts is one of the biggest unsolved problems in astrophysics. Some 3000 of these short-lived bursts of intense gamma-rays have been detected in the last three decades, but it...
Quantum entanglement spreads to Bose condensates
In a Bose-Einstein condensate a gas of atoms is cooled until the de Broglie wavelength of the atoms exceeds the inter-atom spacing. If the atoms are bosons – that is, if they have a “spin&...
Magnets help tell left from right
Like these so-called chiral molecules, circularly polarized light also comes in right and left-handed varieties, and can be used to produce an excess of one type of molecule. However, circularly polar...
Looking inside quantum dots
Manfred Bayer of the University of Wurzburg in Germany, and co-workers in Wurzburg and the National Research Council of Canada in Ottawa, studied indium gallium arsenide quantum dots grown on a galliu...
