Most methods for generating entangled states rely on selecting the entangled pairs, for instance, from a large number of other non-entangled particles. However, last year Klaus Mølmer and Anders ...
One of the biggest challenges in quantum computation is to built “fault tolerant” logic gates. In the mid-1990s it was shown that this requires the time evolution of a quantum sub-system t...
In quantum teleportation the quantum state of an object held by “Alice” is instantaneously sent to “Bob”. The new technique works by having two optical cavities that both conta...
Light is emitted from a quantum cascade laser when an electron falls from an excited energy level in a quantum well to a lower level. The quantum wells are defined by alternating layers of semiconduct...
Only two other methods have previously been used to manufacture quantum dots: electron beam lithography and epitaxy. Lithography is a top down approach in which the beam defines the dot pattern, where...
The medium is made of nanocrystals of zinc sulphide doped with samarium. Although the nanocrystals are only 3 nanometres long, they clump together into larger particles to form a powder that can be us...
Photons from the laser can excite electrons in the water molecules into a so-called anti-bonding state. Molecules in this state can adopt one of two distorted shapes, both of which can dissociate into...
Photons are traditionally detected by converting their energy into an electric signal, which destroys the photon in the process. An additional problem in quantum measurements is that if one variable &...
Landauer was born in Stuttgart in 1927 but had to leave Germany because his family was Jewish. He studied physics at Harvard University in the United States and joined IBM after two years at the Natio...
The pairs are created by illuminating a semiconductor quantum well with a pulsed laser diode. A slight voltage difference on the semiconductor keeps the electron and the hole in separate levels inside...