A strange new world of computing -- where logic bits are not limited to yes-or-no but span every color in the spectrum and circuits and gates operate not individually or hierarchically but holistically -- will be the topic of an international conference hosted by Northwestern University's Robert R. McCormick School of Engineering and Applied Science, Aug. 22 to 27.
Welcome to the world of quantum computing, where miniaturization has taken the computer beyond just smaller and faster into a bizarre realm where quantum effects and the Heisenberg Uncertainty Principle take over. Paradox rules. Mutually exclusive possibilities occur simultaneously, so the atoms or photons of light that carry information like the beads on an abacus can be several places at once.
In this manner a quantum computer can crack enormous problems in minutes that would take today's fastest computers eons to solve. Such computers can quickly search vast databases, or encode -- or attack -- the most sophisticated cryptographic systems.
At least they could if they existed. Physicists and engineers now believe quantum computers may arrive in as little as 10 or 20 years, and they gather from around the world every two years to discuss the latest developments in the already productive fields of quantum communication and measurement. The Northwestern conference, held at Norris University Center, 1999 S. Campus Drive in Evanston, is the fourth international conference and will include presentations by dozens of the world's leading quantum communication pioneers.
"The quantum computer does not yet exist, but that does not prevent us from conceptualizing one," said conference organizer Prem Kumar, professor of electrical and computer engineering at the McCormick School. "Look at flight. The way we fly is not the way birds fly or how people thought we would fly. But we do it -- and we have always dreamed about it."
Two of the speakers at the conference will receive awards for their visionary research:
- Peter Shor, of AT&T Research in Murray Hill, N.J., will be honored for developing software for computers that exist only in theory. His 1994 discovery of an algorithm, or mathematical technique, for factoring large numbers on a quantum computer holds the key to encryption, with implications for everything from national security to automated teller machines and Internet commerce. Electronic data encryption relies on huge numbers that even the most powerful conventional computer cannot factor.
- H. Jeffrey Kimble, professor of physics at the California Institute of Technology, will be honored for his many achievements in quantum hardware, notably for his 1995 demonstration of a rudimentary quantum logic gate that could be a prototype for the building blocks needed to construct a quantum computer.
Other topics will include quantum communication, quantum tomography -- and a fascinating quantum effect called teleportation.
"Anything in a combination of quantum states is in a delicate balance, and any disturbance -- including just the act of reading the result of a calculation in a quantum computer -- upsets it, wiping out the information it contains," Kumar said. "According to the laws of quantum physics, you cannot have a state and measure it also. You destroy it. Quantum teleportation is a way of transporting a quantum state from one place to another without measuring the state. You don't know what the state is, but it's there."
Such quantum effects may sound like science fiction, but scientists have made dramatic advances in the past few years.
"Technology is taking us towards quantum computers," Kumar said. "Perhaps not a quantum computer we could put in a box, but initially toward computers in which quantum effects are essential in fundamental ways."
Sponsors of the Fourth International Conference on Quantum Communication, Measurement & Computing are the Research Institute of Tamagawa University, Northwestern University, the National Security Agency and the Office of Naval Research.