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Several Quantum Calculations Combined At NIST
Al writes "Researchers at the National Institute of Standards and Technology (NIST) have demonstrated a crucial step toward building a practical quantum computer: multiple computing operations on quantum bits. The NIST team performed five quantum logic operations and 10 transport operations (meaning they moved the qubit from one part of the system to another) in series, while reliably maintaining the states of their ions — a tricky task because the ions can easily be knocked out of their prepared state. The researchers used beryllium ions stored within so-called ion traps and added magnesium ions to keep the beryllium ones cool and prevent them from losing their quantum state." In related news, another reader links to an Australian study indicating that quantum computers "can continue to work perfectly even if half their components, or qubits, are missing."
So basically it's quantum physics applied on computer science. Computers of today are based on semiconductors and diodes, which allows us to build electric circuits with memory. In this case, it's voltage applied or voltage off - one or zero. Quantum computing is a whole new world of computing; because it's based on the principles of quantum physics. This means that a quantum computer does not resemble the computers of today at all. In a quantum computer, information is stored in "qubits", which is 0, 1 or "undetermined / both". This is a direct application of the wave/particle duality of matter (wiki: De Broglie-wavelength). Working out how a quantum computer - which behaves totally differently from anything we have today - and constructing such a device is really hard. Theoretically, such devices would be more efficient than our computers - and that's an understatement. This story means that we've taken yet another small step towards practical quantum computers, but also that it'll be reposted at least 100 times before working quantum computers are reality. (Off the top of my head, please correct me if I wrote something in error. Thanks! :)
You just couldn't resist using Everett's interpretation, could you?
I don't think it is a good idea using it to explain something to laymen. They usually end up thinking that quantum mechanics is some kind of inaccessible black magic.
Just to be clear here, it is possible (and it is what's done most of the times) to describe quantum mechanics without ever talking about splitting universes.
Let's see: the qubit can hold some combination of 0 and 1 (NOT 0 and 1). By the same reason (superposition), the quantum computer can perform multiples paths of computation at the same time, which can be used to accelerate the computation of some algorithms.
Quantum computers are quite sensible to noise; it causes decoherence, which can be understood as a loss of quantumness. In other words, a qubit that suffered too much decoherence can't hold a superposition of 0 and 1 anymore.
See? It wasn't that difficult.
entropy happens