Quantum Computation and Quantum Information by Michael E. Nielson and Isaac L. Chuang

One of the most promising scieniifc of East century was the Computers. Computers of initial days were of very large size consisting vacuum tubes ond valves. This has taken over by sernicor-,ductor and transistors which were 0' smaller size and more efficient. The rapid growth in the semiconductor industry hos led to the present form computer on our desktop. This hos initiated the questions about the ultimate limit of this development. AS size Of computer chip is decreasing, if has been predicted by Moor's law that within next twenty year, the size Of a sing bit will be of the order of a single atom. Physical laws governing the atomic phenomena, such cs quantum mechanics, are very different from macroscopic laws. so the computers operating on atomic level will not be Same cs pæsent days computers. This possibility has openee c completely new field of Quantum Computation