Toward On-Chip Quantum Computing

Darum writes "Researchers are working to create devices built on the rules of quantum mechanics. These would allow quantum computers which can do certain problems such as prime number factorization for decryption and simulation of complex systems (such as protein folding) in a tiny fraction of the time required on classical computers. Two papers appearing in this week's Nature raise the possibility of developing such quantum devices by manipulating light signals by semiconductor quantum dots. One of the approaches bases on photonic crystals, which seem pretty ideal for on-chip integration of a full set of computation components. One of the study's authors put up a good background story of this work on CVitae. The author discusses the potential simplicity and microchip scalability of these two quantum-dot 'light switch' systems. This could be good news for quantum information processing and ultra-secure long-distance communication applications. It could also allow all-optical signal processing, which has long been a holy grail for optical communications and could allow extremely fast and low-power optical interconnects."

Re:Questions of SW developer

[blueg3]

Quantum computing is very different. The details are of course very different (such as the operators, and the need for bit-level error checking), but more important to the software developer, the algorithms are fundamentally different. You approach a problem with an entirely foreign set of tools. With quantum computers, it's not a matter of the quantum computer just being "better" -- it has access to a way of doing things that is more powerful (in the mathematical sense) than classical computing.

I don't remember offhand the set of problems that are trivialized by quantum computing, but the difficulty of many problems changes drastically. For example, you can find an element in an unsorted array using a quantum computer in constant time.