The premises behind quantum computing is to use quantum mechanics and quantum physics of atoms or nuclei to perform calculations. These atoms or nuclei are the quantum bits, or qubits, that work as both the processor and the memory for the computer. They can represent more than one state, and many states at the same time. It is not well suited for general computing tasks, but is expected to be used for encryption and code breaking.
Quantum computing was first thought of in the 1970s, but more recently it has become heavily invested and researched by technology corporations. Quantum computers are still in their infancy, but there has already been progress in their production. In 2001, IBM's Almaden Research Center created a quantum computer programmed by radio frequency that is composed of the nuclei of seven atoms (7-qubits) that can interact with each other and successfully factored the number 15. Canadian scientists recently created a 16-qubit quantum computer that is able to solve Sudoku puzzles. HP scientists created a quantum computer equivalent of a transistor. In 2009, researchers were able to control the actions of a single qubit in a matrix of other qubits which is a step towards creating more advanced quantum computers.
References: Morely, Deborah; Parker, Charles. Understanding Computers Today and Tomorrow. Course Technology, 2011. Pages 83-84. Print.
Waldner, Jean-Baptiste. Nano-informatique Et Intelligence Ambiante: Inventer L'ordinateur Du XXIe Siècle. Paris: Hermès Science Publications, 2007. 157. Print.