Tag Archives: quantum computing

Australian researchers create world’s first working quantum bit

Posted on by

This enabled them to form a quantum bit or “qubit”, the basic unit of data for quantum computers, which promise to solve complex problems “that are currently impossible on even the world’s largest supercomputers,” according to team leader Dr Andrea Morello.

via Australian researchers create world’s first working quantum bit – Professor Andrew Dzurak, Dr Andrea Morello, university of new south wales, quantum bit, quantum computing – CIO.

The paper’s lead author, UNSW PhD student Jarryd Pla, said researchers had been able to “isolate, measure and control an electron belonging to a single atom, all using a device that was made in a very similar way to everyday silicon computer chips.”

Scientists Establish First Working Quantum Network

Posted on by

The team has managed to rig up a laser to fire and hit the first networked atom in a way that the atom preserves its quantum state, but also produces a photon with that information plastered onto it. The photon then shoots off down the fiber optic cable delivering it to the second atom. Network achieved. On top of that, the researchers managed to get the two networked atoms to entangle, which means the network should be completely scalable to something along the lines of an Internet.

via Scientists Establish First Working Quantum Network | Geekosystem.

NOVA series on quantum mechanics.

And another link from Cornell: Does quantum entanglement imply faster than light communication?

Say you agree to send out two beams of light to your two friends who live on opposite sides of the galaxy (you live in the middle). Ahead of time you tell them that if one of the beams of light is red the other will be blue. So you send the blue beam to your friend on one side and immediately she knows that your other friend is recieving a red beam at the same time. Aha! You say, my friends have now communicated at a speed faster than the speed of light and violated relativity, but no real information has been passed between them. You have told both of them at a normal sub-luminal speed about what you just did and that’s all. (A way of proving there’s no faster than light communication is that you could lie and send them both the same coloured beam of light and they would never know!).

Shor’s algorithm

Posted on by

If a quantum computer with a sufficient number of qubits were to be constructed, Shor’s algorithm could be used to break public-key cryptography schemes such as the widely used RSA scheme. RSA is based on the assumption that factoring large numbers is computationally infeasible. So far as is known, this assumption is valid for classical (non-quantum) computers; no classical algorithm is known that can factor in polynomial time. However, Shor’s algorithm shows that factoring is efficient on a quantum computer, so a sufficiently large quantum computer can break RSA. It was also a powerful motivator for the design and construction of quantum computers and for the study of new quantum computer algorithms. It has also facilitated research on new cryptosystems that are secure from quantum computers, collectively called post-quantum cryptography.

via Shor’s algorithm – Wikipedia, the free encyclopedia.

A Quantum Computer Finds Factors

Posted on by

A quantum computer, on the other hand, promises to factor a number of any size in one operation and, if one can be built, the future of the PKI looks bleak and we would have to find encryption methods that were safe against a quantum attack.

via A Quantum Computer Finds Factors.

Of course, factoring 15 isn’t something that is going to threaten the PKI and cryptography in general, but factoring  larger numbers is just a matter of increasing the number of qubits and this approach does seem to be a scalable solid state approach.

Physicists Create a Working Transistor From a Single Atom

Posted on by

In contrast to conventional computers that are based on transistors with distinct “on” and “off” or “1” and “0” states, quantum computers are built from devices called qubits that exploit the quirky properties of quantum mechanics. Unlike a transistor, a qubit can represent a multiplicity of values simultaneously.

via Physicists Create a Working Transistor From a Single Atom – NYTimes.com.

Quantum Processor Hooks Up with Quantum Memory

Posted on by

Although quantum computing is now mostly a research subject, it holds out the promise of computers far more capable than those we use today. The power of quantum computers comes from their version of the most basic unit of computing, the bit. In a conventional computer, a bit can represent either 1 or 0 at any time. Thanks to the quirks of quantum mechanics, the equivalent in a quantum computer, a qubit, can represent both values at once. When qubits in such a “superposition” state work together, they can operate on exponentially more data than the same number of regular bits. As a result, quantum computers should be able to defeat encryption that is unbreakable in practice today and perform highly complex simulations.

via Quantum Processor Hooks Up with Quantum Memory – Technology Review.

Reading this makes my head want to explode.