Quantum computers rely on fundamentally different principles to today’s computers, in which each bit represents either a zero or a one. In quantum computing, each bit can be both a zero and a one simultaneously. So while three conventional bits can represent any of eight values (2^3), three qubits, as they’re called, can represent all eight values at once. That means calculations can theoretically be performed at much higher speeds.
Tag Archives: qubits
The Mathematical Trick That Helped Smash The Record For The Largest Number Ever Factorised By A…
And in any case, because this trick works using only 4 qubits, it can easily be reproduced on any classical computer. So it’s not so useful after all.
Here’s a paper on this subject:
[1411.6758] Quantum factorization of 56153 with only 4 qubits.
Recycled photons set fresh quantum computing record
Laing’s team is also working towards that end. As part of the recycling technique, the researchers chained together two logic gates – a first for an optical quantum computer and an essential step in terms of hardware for building more complex devices. “To me, this achievement is more important than factoring 21, although to do so is an excellent demonstration of the technique’s power,” says Browne.
via Recycled photons set fresh quantum computing record – physics-math – 23 October 2012 – New Scientist.
Australian researchers create world’s first working quantum bit
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.
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
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!).
Quantum Processor Hooks Up with Quantum Memory
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.