Quantum Logic Gate Created Using Excitons

Roland Piquepaille writes "In this article, PhysicsWeb reports that researchers in the U.S. "have taken another important step towards making a quantum computer. [They] have created a logic gate using two electron-hole pairs -- also known as "excitons" -- in a quantum dot." According to Wikipedia, "an exciton is a combination of an electron and a hole in a semiconductor or insulator in an excited state These physicists from the University of Michigan and other labs made a quantum dot by using a thin gallium arsenide layer stuck between two aluminium gallium arsenide barriers. And electrons trapped in the middle layer were excited by light to create a quantum logical gate with four states. The group says this could be useful "in other approaches to quantum computing based on the optical control of electron-spin qubits in quantum dots.." This summary contains more details."

Comments

Re:In the future!

[DrWho520]

How much about a standard computer must you know to run anything today? If you are coding in assembly, admittedly you must have an understanding, but do you need to know the base logic of the computer? Do you really have to understand how a transistor or a JK-flip-flop works to write C, C++ or Java? You certainly do not to build a machine. Its just a bunch of black boxes.

The true power of quantum computing is the idea of a mixed state, the shades of gray if you will, that will be possible with quantum elements. While logic gates take strictly binary inputs (bits), quantum gates will take superpositions of the 1 and 0 states (qubits). Ask a simple question, is it cloudy outside? A bit either says yes or know depending upon a threshold of some sort. Who sets the threshold, does everyone agree on the threshold, and how accurately is the threshold mesured? A qubit can give you a mixture of yes and know, relaxing the systems. Its very similar to fuzzy sets, as elements are not strictly in or out of a set.

There will be a learning curve. Unfortunately, until there are a large number of gates of a specific type, a deffinitive logic process (fuzzy logic, if you will) cannot be decided upon. (Maybe there will be serveral types, and Intel works with one type of qubit logic and AMD works with a different.) But the logic system is what you will need to understand, that is what people understand now. Is it really a simple process to break down everything into yes or know? You don't need a PhD. for that. I think the fuzziness of a quantum system is much closer to reality than that of binary.

I picked up my PhD. (Posthole Digger) at the hardware store.