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CHAPTER 2
BASIC CONCEPTS AND RELATED WORKS
2.1 Quantum Computing and Quantum Information Theory
Moore’s law has been holding true throughout the last decades of the twentieth century.
Nevertheless, it seems obvious that an exponential increase of the number of components on
a solid state chip will eventually hit a “wall” and this dream will eventually end sometimes
during the first two decades of the twenty-first century. Conventional approaches to the
fabrication of computer technology are running up against fundamental difficulties of size.
Quantum effects are beginning to interfere in the functioning of electronic devices as they
become smaller and smaller. Another physical limitation is the heat removal for a circuit
with densely packed logic gates. The amount of heat generated per volume increases with
the calculated power of the circuit, while the ability of remove heat is proportional to the
the surface area.
One possible solution to the problem posed by the eventual failure of Moore’s law is to
move to a different computing paradigm. One promising solution is provided by quantum
computation, based on the idea of using quantum particles which obey the rules of quantum
mechanics, instead of classic physics. In the early 1980s, Feynman introduced this idea that
quantum computers, which used quantum mechanics intrinsically, might be more powerful
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