Quantum Computing with Molecules

by Neil Gershenfeld and Isaac L. Chuang

Factoring a number with 400 digits a numeric al feat needed to break some security codes would take even the fastest super computer in existence billions of years, but a newly conceived type of computer, one that exploits quantum-mechanical interaction, might complete the task in a year or so. Thereby defeating many of the most sophisticated encryption schemes in use sensitive data are safe for the time being, because no one has been able to build a practical quantum computer. But researchers have now demonstrated the feasibility of this approach. Such a computer would look nothing like the machine that sits on your desk surprisingly it might resemble the c up of coffee at its side. Several reseach groups believe quantum computers based on the molecules in a liquid might one day over come many of the limits facing conventional computer. Roadblocks to improving conventional computers will ultimately arise from the fundamental physical bounds to miniaturization (for example because transistors and electrical wiring cannot be made slimmer than the width of an atom). Or they may come about for practical reasons most likely because the facilities for fabricating still more powerful microchips will become prohibitively expensive. Yet the magic of quantum mechanics might solve both these problems.