SW BULLETIN - August 20, 1999
PHYSICS: QUANTUM COMPUTERS
In a quantum computer, information is stored via quantum
variables such as spins, photons, or atoms. The elementary unit
is a two-state quantum system called a "qubit". Electron beam
lithography is a lithographic method in which a radiationsensitive
film is exposed to a computer controlled electron beam;
the method can be applied to the microdesign of circuits. In
general, a Josephson junction is a thin insulator separating two
superconductors. J.E. Mooij et al (NL US) now report the design
of a qubit that can be fabricated with conventional electron beam
lithography and which is suited for integration into a large
quantum computer. The qubit consists of a micron-sized loop with
3 or 4 Josephson junctions, the 2 qubit states having persistent
currents of opposite direction. The authors suggest that apart
from its quantum computing potential, the proposed qubit should
be of considerable interest for fundamental studies of
macroscopic quantum coherence. (SCI)
Editor: PSYCHE: An International Journal of Research on Consciousness Board Member: The Association for the Scientific Study of Consciousness http://psyche.cs.monash.edu.au/ http://www.phil.vt.edu/ASSC/