Monday, August 09, 2004

Quantum Information Systems

I just read a very interesting piece over at on the new science of Quantum Information. What this new science essentially aims to facilitate is the exponential increase in the speed of information processing. Thus, quantum information examines the universe of quantum interactions in order to explain how they relate to classical explanations of thermodynamics and entropy.

Where Classical Physics and Quantum Mechanics have diverged is in their ability to make sense of each other. The perceptibility and predictability of the physical world allows for a somewhat palpable understanding of our physical laws. Though, at a smaller quantum level, the coherence of the physical world becomes highly variable, unquantifiable, and volatile.

Quantum Mechanics has attempted to explain various quantum states, though only in abstracted settings—such as isolated atoms. Although still theoretical, Quantum Information science posits that the ability to control, arrange, and distribute quanta in an information system—or in any system, for that matter—may dramatically increase the speed with which information is processed.

This, to be sure, means the possible creation of incredible super-computers that would be able to do computations far faster than current computers-- so much so, that what may take computers now days and months to compute, would take these super-computers milliseconds. These are the possible operating principles:

1. Identify a physical resource. A familiar classical example is a string of bits. Although bits are often thought of as abstract entities--0's and 1's--all information is inevitably encoded in real physical objects, and thus a string of bits should be regarded as a physical resource.

2. Identify an information-processing task that can be performed using the physical resource of step 1. A classical example is the two-part task of compressing the output from an information source (for example, the text in a book) into a bit string and then decompressing it--that is, recovering the original information from the compressed bit string.

3. Identify a criterion for successful completion of the task of step 2. In our example, the criterion could be that the output from the decompression stage perfectly matches the input to the compression stage.

Another interesting application of the Science of Quantum Mechanics is Error Correction. Telling time is no doubt an imprecise science, given that various distortions of a physical variety perturb the fluidity of our actual measurements. However, there may be an answer to this problem:

Quantum error-correcting codes are a triumph of science. Something that brilliant people thought could not be done--protecting quantum states against the effects of noise--was accomplished using a combination of concepts from information science and basic quantum mechanics.

What Thermodynamics did for the steam engine in the 18th and 19th century, Quantum Mechanics can do for computer systems, information technology, and complex systems in the 21st and 22nd century--and beyond.

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