Published February 14, 2001
As computers become faster, their critical components must be wired closer together. Shortening the path for electrons to travel will inevitably reach a limit called the speed of light.
By the year 2012, transistors are predicted to be about three atoms thin. Science has been engrossed with the study-of-the-small, hurling inevitably to the perimeter of quantum physics.
The Quantum computer hardware is not “hard” at all, but is instead a vessel of liquid or gas. These earliest endeavors have been either of the Nuclear Magnetic Resonance (NMR) type, or the Ion Trap. Both are very primitive compared to conventional silicon-based computers, but incomparably advanced in other ways.
A most unusual characteristic is that tampering, touching or even looking at the atoms in a quantum computer distorts the results. Scientists have for some time been aware that we influence matter by our thoughts or physical presence. Early particle accelerator tests have demonstrated that technicians’ expectations have altered the subatomic particle traces and their interactions.
The most distinctive advantage of a quantum computer is that it’s an unique process liken to very fast parallel processing. Crude models can search and retrieve database information faster than integrated circuits; and cryptograph security encoding/decoding is child’s play. For these purposes, the military and governments are very interested.
In a standard computer, one bit represents either a value of 0 or 1. But a quantum bit, called a qubit, can be represented by an atom or photon with a value of any and all numbers between 0 and 1. Many possibilities can be computed simultaneously and instantaneously. It is so unlike anything else, logic is suspended.
Only eight years ago, AT&T Labs scientist Peter Shor invented a quantum factorization algorithm. Coupled to a quantum computer today, his obscure contribution has resulted in this remarkable oddity.
Lov Grover of Bell Labs varied Shor’s process to realize the immense power for searching databases. With only a first name and perhaps a street number in a metropolitan area, the quantum computer finds a match very quickly. A conventional computer sequencing through a very large list requires 50 times more steps than the relatively simple quantum; and the quantum computer parallel processes these practically in an instant.
Deepak Srivestava of NASA’s Ames Research Center believes that Grover’s algorithm can be modified for space exploration. Stanford University, AT&T Labs, and Lucent’s Bell Labs are each engaged in their own diverse quantum computing projects.
Pioneers in this unassuming field also include Dr. Richard Hughes of the Department of Energy’s Los Alamos National Labs; physicist David Wineland of the National Institute for Standards and Technology; IBM’s Isaac Chuang and Nabil Amer. Toshiba, British Telecom, and Japan’s NTT are to be included in recognition of developing quantum encryption techniques.
Hewlett-Packard’s objective interest in quantum computing is to reduce the size of today’s computers. Developing a new branch of science would be a distinction of unappreciated consequence.
The mechanism by which a NMR machine computes is easier to observe than to explain. Somehow input instructions nudge chloroform atoms, which in turn spin carbon atoms to program the computer. Dr. Hughes of Los Alamos National Labs says, “Scaling above 17 qubits has so far proven to jeopardize the quantum properties.”
“Not even a quantum computer,” says Mr. Grover, “can crack computing’s classic conundrum of the traveling salesman problem—which is to calculate the shortest route a salesman can travel between multiple cities. A similar but more complex task is to efficiently route packets of information across the Internet of possibly millions of locations.”
If qubits can be insulated from external thought influences, the form of the quantum computer might be solid state. Mr. Amer hypothecates that eliminating heat as electrons move along a wire could replicate the atoms in a liquid. That ideal stases is called super-conductivity.
Quantum computing will likely emerge for productive use about the time that the limits of conventional computers closely approach the physical limits of the speed of light. Beyond that is the unimaginable quantum possibilities or something else equally mystifying.