Defects boost optical communications
In a photonic crystal the periodic variation of the dielectric constant results in a range of ‘forbidden’ frequencies called a photonic bandgap (PBG). Electromagnetic waves with a ‘f...
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...
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...
New light on organic LEDs
Light emission from organic materials occurs through two separate processes: fluorescence – the process by which today’s organic semiconductors produce light – and phosphorescence. I...
Conductivity measurements made on a single strand of DNA
The Delft group fabricated the electrodes by making a slit in a silicon nitride film with standard lithography. A series of platinum layers were then sputtered across the slit until the gap was reduce...
Polymer lasers without mirrors
The waveguide structure was created by pouring a mixture of copolymer solution and molecular laser dye into a mould situated on top of a silicon wafer. The solution was allowed to solidify over 12 hou...
Top quark and Bell’s inequalities top PhysicsWeb Nobel poll
Every year the Foundation asks 3000 physicists to nominate individuals for the prize, and compiles a short-list of 250 candidates. These names are then whittled down to a list of 30, from which the wi...
Heat can produce ultrasound
Currently most ultrasound devices convert an electrical signal directly into mechanical vibrations through the piezoelectric effect. But these devices only operate over a narrow frequency range and ha...
Parisi wins Dirac medal
Parisi won the award for his work in a wide number of fields. The official citation highlights “his study of scaling violations in deep inelastic processes (Altarelli-Parisi equations), a model ...
Vortex look for lasers
Scheuer and Orenstein used so-called vertical cavity surface-emitting lasers. In these devices the light is emitted from the top of the active region of the laser, rather than from the edge as in conv...
