The notion of a quantum computer was first put forth by Richard Feynman in 1982. He suggested that the only way to effectively simulate a quantum system was with another quantum system. The question of whether quantum computation could be more powerful than classical computation in general was first pioneered by David Deutsch in the mid-1980’s. He developed the notion of a universal quantum computer as well as the first quantum algorithm, as opposed to a simulation. It was not until 1994, when Peter Shor published an algorithm that could factorize large numbers into prime numbers exponentially faster than ever before, that the field of quantum computation really began to flourish.

The reason Shor’s factoring algorithm is so responsible for the burgeoning of the field of quantum computation is security. The most popular encryption schemes for digital information, i.e., the encryption used to prevent people from stealing your credit card information when you buy something on the internet, are safe because people cannot factor a large number into two primes in any amount of reasonable time. Shor’s algorithm, if we had a quantum computer, could solve this problem in an instant. Though still not known for sure, many people speculate that a quantum computer could solve an entire class of problems that today’s computers find impossible to solve.

Besides the enormous computational power a quantum computer seems to offer, the systems that could make up quantum computers also present fascinating physics and engineering challenges. The fundamental unit of information in today’s computers is the bit. In a quantum computer these bits would be replaced by their quantum cousins, qubits. An accurately manipulated and well-behaved single qubit is the most fundamental component of a quantum computer, and it is an extremely interesting and challenging problem. For a quantum computer you would also need to couple lots of qubits together, which is another fascinating challenge. And of course all these sensitive qubits must be shielded from all the microscopic noise that constantly surrounds us but doesn’t bother us, but which would ruin all hope of computing with the qubits.

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