QUANTA, CIPHERS AND COMPUTERS

Abstract

On the atomic scale, matter obeys the rules of quantum mechanics which are quite different from the classical rules that determine the properties of conventional computers. Today's advanced lithographic techniques can etch logic gates and wires less than a micron across onto the surfaces of silicon chips. Soon they will yield even smaller parts and inevitably reach a point where logic gates are so small that they are made out of only a handful of atoms. So, if computers are to become smaller in the future, new, quantum technology must replace or supplement what we have now. This article provides a grand overview of quantum information theory from the concept of quantum bits (qubits) to entanglement to quantum computation to quantum cryptography.