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&...
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...
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...
New materials stretch the imagination
The Poisson’s ratio of a material is defined as nij = –ej/ ei, where ej is the lateral strain in the j direction that is caused when a strain ei is applied in the longitudinal i direction....
Physics, polymers and pesticides
Physicists have studied the interaction of water with surfaces for centuries. Felix Savart, for instance, first studied shocks in shallow water in 1833. It is now well known that the maximum diameter ...
RHIC makes its debut
One of RHIC’s main goals is to produce a quark-gluon plasma – the state of matter that is thought to have existed just millionths of a second after the big bang. Quarks are normally confin...
