Hewlett-Packard Co. (HP) and the Massachusetts Institute of Technology (MIT) have announced a joint US$2.5 million quantum computing project to advance computing development beyond its current physical limits.
The project, announced last week, is part of a $25 million, five-year alliance launched in June 2000. Researchers at HP Labs in Palo Alto, California and Bristol, England will work with their counterparts in MIT's Media Lab, including Neil Gershenfeld and Isaac Chuang. Gershenfeld and Chuang are described as pioneers by HP in its press release, because of their past work in actually building and operating a simple quantum computer.
Quantum computing development is necessary because the current classical computing model is reaching its limit, said an HP spokesman today.
"Moore's Law is going to reach its natural conclusion because of the physical limitations of present technology. When you get to the atomic scale you can't take it much further," the spokesman said. "So we have to use the laws of quantum physics, as far as they are understood, to take computing further," he said.
Quantum computing research is farsighted, and it may take 10 years to develop a fully operational quantum computer, "but if you want to keep using computers in the way we have been, and to keep Moore's Law working, then we have to keep moving forward," the spokesman concluded.
Quantum computing uses quantum systems to perform calculations. The basic unit of computation used is the qubit or quantum bit, a quantum system with two states. Unlike classical bits, the qubit can be not just 0 or 1 but a superposition of both, in differing proportions. While the classical bit can store any number between 0 and 255 on each of its eight bytes, the qubit can store all the numbers between 0 and 255 on a byte of eight qubits. This allows much more information to be stored on a quantum bit than a classical bit, and allows parallelism in processing: one calculation can give the answer for all the numbers on the byte at the same time, according to an explanation posted on the MIT Web site.
However, problems arise when it comes to reading the information back. Any interactions with the environment -- including trying to read the information stored -- affect the qubits so that they change from a pure quantum state to a mixed state. This is known as decoherence and any reading taken from this state will be wrong. Various techniques have been developed to avoid decoherence including one by Gershenfeld and Chuang that makes use of a chemistry technique called nuclear magnetic resonance (NMR) spectroscopy.
Hewlett-Packard can be reached at +1-800-752-0900 and is available online at http://www.hp.com. MIT is online at http://web.mit.edu