Tag: photons

Scientists grab photons on silicon chips

Posted on January 12, 2015 by - News

MIT building - Wikimedia CommonsResearchers at the Massachusetts Institute of Technology (MIT) claim to have built light detectors that can register individual photons on a silicon chip.
The MIT team said they have increased the accuracy of the detectors and transferred those that work to an optical semiconductor.
The approach gives denser and larger arrays, said the MIT team with 100 times better accuracy than previous arrays.
The researchers first built a silicon optical chip using regular manufacturing processes. Then they grow a flexible film of silicon nitride on a separate silicon chip – and then the superconductor niobium nitride is despised in a pattern that can detect photons.
Gold electrodes are deposited on both ends of the detector.
Dirk Englund, a professor at MIT and part of the team, said the project was aided by IBM and NASA’s Jet Propulsion Lab.
Previous detectors only managed to pick up 0.2 percent of single photons, but MIT said detectors on its chip reached 20 percent.
We’re still a way away from quantum computing though – because MIT says 90 percent or more is needed for a working quantum circuit.

 

Quantum theory may help net security

Posted on January 7, 2015 by - News

National-Security-Agency--008Scientists at the Griffith University in Queensland claim quantum physics will help protect data on the internet.
The researchers said that so-called “quantum steering” can be used to improve data security over long distances.
Project leader Professor Geoff Pryde boasts that the method his team are engineering promises “absolutely secure information transfer”.
He said: “Your credit card details or other personal data sent over the internet could be completely isolated from hackers.”
The scientists used special photon quantum states to program a measurement device at each step of sending code.
He said that quantum systems would secure long distance comms by generating random and uncrackable code.
But that would rely on both parties sharing systems.  But his team has invented something called quantum steering, which is used to maintain communication security and removing trust in third party devices.

 

Scientists crystallise light

Posted on September 10, 2014 by - News

Princeton University crystallised lightPrinceton University scientists have locked together photos and created crystallised light.

The reason for the scientists doing this somewhat unusual thing is because they’re aiming at developing room temperature superconductors.

Hakan Tureci, an assistant professor of electrical engineering, said: “We are interested in exploring – and ultimately controlling and directing – the flow of energy at the atomic level. The goal is to better understand current materials and processes and to evaluate materials that we cannot yet create.”

The research could also lead to more efficient computers.  Current computers use classical mechanics. But, said the researchers: “The world of atoms and photons obeys the rules of quantum mechanics, which include a number of strange and very counterintuitive features. “

Building a quantum computer would allow many problems to be solved that can’t be using the mechanical model.  Building a quantum computer is, however, very difficult, the researchers said.

Tureci pointed out that sometimes light acts like a wave and other times a particle – a photon. “Here we set up a situation where light effectively behaves like a particle in the sense that two photons can interact very strongly,” he said. “In one mode of operation light sloshes back and forth like a liquid, in the other it freezes.”