High school chemistry
36 views | +0 today
Follow
High school chemistry
Exploring topics that revolve around high school chemistry
Your new post is loading...
Your new post is loading...
Rescooped by Anne M Petersen from Amazing Science
Scoop.it!

WIRED: The Race to Bring Quantum Teleportation to Our World

WIRED: The Race to Bring Quantum Teleportation to Our World | High school chemistry | Scoop.it
There is an international quantum teleportation space race heating up. Around the world, countries are investing time and millions of dollars into the technology, which uses satellites to beam bits of quantum information down from the sky and and could profoundly change worldwide communication.

 

This is not a maybe-sort-of-one-day quantum technology. Quantum teleportation has been proven experimentally many times over and researchers are now eyeing the heavens as their next big leap forward. Most of what remains are the nuts and bolts engineering challenges (and some more money) before it becomes a thing of the present.

 

Though it may be disappointing to hear, quantum teleportation is not about instantly sending a person or object between two places – this is no “Beam me up, Scotty,” or “Bampf!” Instead, the technique involves the perhaps even freakier task of separating a subatomic particle from its quantum state.

 

Though the team’s paper was purely theoretical at the time, scientists since then have done many experiments teleporting particles over longer and longer distances. In the past year, a team from China and another in Austria set new records for quantum teleportation, using a laser to beam photons through the open air over 60 and 89 miles, respectively. This is many times farther than the previous record of 10 miles, set in 2010 by the same Chinese team. With scientists extending quantum teleportation to such distances, many are already considering the next step: zapping particles and information from an orbiting satellite to a relay station on Earth.

 

If developed, quantum teleportation satellites could allow spies to pass large amounts of information back and forth or create unhackable codes. Should we ever build quantum computers – which would be smaller and exponentially more powerful than modern computers, able to model complex phenomenon, rapidly crunch numbers, and render modern encryption keys useless – they would need quantum teleporters in order to be networked together in a quantum version of the internet.

 

China plans to launch a satellite with a quantum teleportation experiment payload in 2016 and the European, Japanese, and Canadian space agencies are hoping to fund their own quantum teleportation satellite projects in the coming years. Conspicuously, the U.S. is far behind the pack because of a bureaucratic reshuffling that left quantum communication research experiments without government support in 2008. Whoever loses this new competition could fail to capitalize on the promise of quantum communication altogether.


Via Dr. Stefan Gruenwald
more...
No comment yet.
Rescooped by Anne M Petersen from Amazing Science
Scoop.it!

Schrödinger's Cat is Alive! Scientists measure a system's quantum state without collapsing its superposition

Schrödinger's Cat is Alive! Scientists measure a system's quantum state without collapsing its superposition | High school chemistry | Scoop.it

Schrödinger's cat, the enduring icon of quantum mechanics, has been defied. By making constant but weak measurements of a quantum system, physicists have managed to probe a delicate quantum state without destroying it – the equivalent of taking a peek at Schrodinger's metaphorical cat without killing it. The result should make it easier to handle systems such as quantum computers that exploit the exotic properties of the quantum world.

 

Quantum objects have the bizarre but useful property of being able to exist in multiple states at once, a phenomenon called superposition. Physicist Erwin Schrödinger illustrated the strange implications of superposition by imagining a cat in a box whose fate depends on a radioactive atom. Because the atom's decay is governed by quantum mechanics – and so only takes a definite value when it is measured – the cat is, somehow, both dead and alive until the box is opened.

 

Researchers had suggested it should be possible, in principle, to make measurements that are "gentle" enough not to destroy the superposition. The idea was to measure something less direct than whether the bit is a 1 or a 0 – the equivalent of looking at Schrödinger's cat through blurry glasses. This wouldn't allow you to gain a "strong" piece of information – whether the cat was alive or dead – but you might be able to detect other properties.

 

Now, R. Vijay of the University of California, Berkeley, and colleagues have managed to create a working equivalent of those blurry glasses. "We only partially open the box," says Vijay. The team started with a tiny superconducting circuit commonly used as a qubit in quantum computers, and put it in a superposition by cycling its state between 0 and 1 so that it repeatedly hit all the possible mixtures of states.

 

Vijay and colleagues used a new kind of amplifier that let them turn up the signal without contaminating it. They found that their qubit stayed in its oscillating state for the entire run of the experiment. That was only about a hundredth of a second – but, crucially, it meant that the qubit had survived the measuring process.

 

"This demonstration shows we are almost there, in terms of being able to implement quantum error controls," Vijay says. Such controls could be used to prolong the superpositions of qubits in quantum computing, he says, by automatically nudging qubits that were about to collapse. The result is not perfect, points out Howard Wiseman of Griffith University in Brisbane, Australia, in an article accompanying the team's paper. "But compared with the no-feedback result of complete unpredictability within several microseconds, the observed stabilization of the qubit's cycling is a big step forward in the feedback control of an individual qubit."


Via Dr. Stefan Gruenwald
more...
No comment yet.