MIT creates diode for light, makes photonic silicon chips possible. Light-emitting diodes (LEDs) are a cornerstone of consumer tech. They make thin-and-light TVs and smartphones possible, provide efficient household, handheld, and automobile illumination, and, of course, without LEDs your router would not have blinkenlights. Thanks to some engineers from MIT, though, a new diode looks set to steal the humble LED’s thunder. Dubbed a diode for light, and crafted using standard silicon chip fabrication techniques, this is a key discovery that will pave the path to photonic (as opposed to electronic) pathways on computer chips and circuit boards. In electronics, a diode is a gate that only allows electrons to pass in one direction (and with an LED, it also emits light at the same time).
In this case, the diode for light — which is made from a thin layer of garnet — is transparent in one direction, but opaque in the other. Read more at MIT. Quantum qubits found in cheap, mass-produced semiconductor. Don your quantum computing tinfoil hat, for we have epic news that might just result in qubits replacing bits before the decade is out: Physicists at UC Santa Barbara have discovered a quality of silicon carbide — a material commonly used in the manufacture of semiconductors — that can be used to perform quantum computing. Silicon carbide is a compound that has some 250 crystalline forms, but its 4H polytype (pictured below right) has an imperfection that traps electrons. The spin of these electrons can then be manipulated and measured (addressed) with optical wavelengths.
In short, silicon carbide is an array of solid-state, addressable qubits. The reason this is big news is because silicon carbide traps electrons at room temperature, and (so far) the only other material to exhibit this property is diamond. How does this news actually affect you, though? Read more at UC Santa Barbara [Image credit: 1 & 2] Entangled diamonds vibrate together. A pair of diamond crystals has been linked by quantum entanglement. This means that a vibration in the crystals could not be meaningfully assigned to one or other of them: both crystals were simultaneously vibrating and not vibrating. Quantum entanglement — interdependence of quantum states between particles not in physical contact — has been well established between quantum particles such as atoms at ultra-cold temperatures.
But like most quantum effects, it doesn't tend to survive either at room temperature or in objects large enough to see with the naked eye. Diamonds have been linked with quantum entaglement — 'spooky action at a distance'. A team led by Ian Walmsley, a physicist at the University of Oxford, UK, found a way to overcome both those limitations, demonstrating that the weird consequences of quantum theory apply at large scales as well as at very small ones. An entangled web Weird as it is, quantum entanglement is real — and could be useful. Photons and phonons. Light created from a vacuum: Casimir effect observed in superconducting circuit. Scientists at Chalmers have succeeded in creating light from vacuum -- observing an effect first predicted over 40 years ago. In an innovative experiment, the scientists have managed to capture some of the photons that are constantly appearing and disappearing in the vacuum. The results have been published in the journal Nature.
The experiment is based on one of the most counterintuitive, yet, one of the most important principles in quantum mechanics: that vacuum is by no means empty nothingness. In fact, the vacuum is full of various particles that are continuously fluctuating in and out of existence. They appear, exist for a brief moment and then disappear again. Since their existence is so fleeting, they are usually referred to as virtual particles. Chalmers scientist, Christopher Wilson and his co-workers have succeeded in getting photons to leave their virtual state and become real photons, i.e. measurable light. First quantum jiggles detected in solid object - physics-math - 28 January 2012. NOTHING sits still. Even at absolute zero, when the thermal jiggling of matter is frozen, all things must still buzz to the tune of quantum mechanics. Now this subtle jittering has been detected in a small silicon bar, the first solid object ever to reveal its quantum vibrations.
This phenomenon, called zero-point fluctuation, is a consequence of Heisenberg's uncertainty principle, which says that we can never pin down the precise position and motion of any object. So far zero-point energy has only been seen directly in single atoms or small collections of particles. The new experiment uses a silicon bar about 12 micrometres long and less than a micrometre across. Some photons from this laser got a shift in energy when they hit the vibrating bar. "Seeing these effects in large objects can provide us with a way to probe the foundations of quantum mechanics," says Caltech team member Amir Safavi-Naeini. More From New Scientist Shroud of Turin depicts Y-shaped crucifixion (New Scientist)