## QUANTUM INFORMATION PROCESSING

Perhaps the two most perplexing behaviors of quantum particles are superposition and entanglement. But in spite their spookiness, many scientists anticipate revolutionary technologies to emerge that can exploit these wonderfully strange properties of the quantum world.

Interestingly, the principle of superposition, that once was such a source of confusion for the interpretation of quantum mechanics, has become an indispensable doctrine in the emerging science of quantum information processing. And in spite of Einstein’s suspicion, quantum mechanics is inherently non-local and generations of experiments performed since the 1980s have repeatedly affirmed its legitimacy. Today most physicists believe that the EPR paradox is really not a paradox. It “appears” paradoxical because our everyday or classical intuitions do not agree with the physical reality of the subatomic world. Even a few years ago, the goal of researchers was to understand the laws of nature according to how quantum systems functioned. Nobody seriously believed that the strangeness of quantum mechanics could be exploited in designing real world applications. Today the new goal is to manipulate and control quantum systems so that they behave in a prescribed way. Scientists are now beginning to understand how to exploit the idiosyncrasies of the subatomic world in designing practical applications.

The area of information science that makes direct use of quantum mechanical phenomena is called Quantum Information Theory. It can be divided into two rough areas: Quantum Communication and Quantum Computation. Quantum Communication is devoted primarily to studying the distribution of quantum states between entities that are spatially separated, and include applications such as quantum cryptography, teleportation and dense coding. Quantum computation on the other hand, makes direct use of quantum-mechanical phenomena, such as superposition and entanglement, to perform calculations (operations on data).