Quantum computing has been around for a while, but is still in its infancy. It has the potential to be the next big leap in the microprocessor technology.
Conventional computers work in binary. Data is encoded and transferred in ‘bits’ which are either a: 0 or 1. The one being when an electronic charge is being conducted through the circuit and a zero for when there is no charge. In quantum computing, they use what is called a ‘qubit’, which can be a 0 or 1 or a superposition of both (both 1 and 0 at the same time). As you can see, this is a break from the traditional computing paradigm.
Quantum computing, as the name suggests, is based on Quantum Physics (quantum mechanics), as opposed to atomic ‘classical’ physics. The quantum universe (the sub atomic) behaves in a way that is different, and is even at odds with classical physics. The rules that govern the atom particles, simply do not apply to the sub atomic. In this world, quantum phenomena can exist and not exist at the same time. So here you can see how data can be given the property a positive (1), a negative (0) and an in-between state (both 0&1). It is this factor alongside the quantum theory of entanglement that quantum computing scientists are seeking to exploit.
The advantage of quantum computer processor is something which is called parallelism. This means that several processes or operations can be carried out at the same time; solving computation problems in a fraction of the time. With quantum computing the increase is exponential.
The biggest obstacle that has to be overcome in quantum computing is something called decoherence. As soon as the qubit interacts with its environment, it reverts to a normal state of 1or 2. Quantum computer processors are still largely theoretical and experimental, because of the problem of decoherence. When dealing with things that are very small and unstable, it is difficult to hold them together within the component that you are trying to build. They could just as easily disappear and materialize on the other side of the universe as stay and do what people would like them to do. Such is the way with quantum materials.
There is a lot of interest in making the quantum computer happen. Governments and the military in particular have invested in this area. Another factor is the commercial one. Consumers of I.T. are looking for ever faster and ever smaller computers, laptops, smartphones and tablets. It could be all of these factors that enable this to happen. There is a lot research in this area, but according to John Martinis, the world is ten years away from seeing the first mainframe based on this technology and a long way from seeing desktop computers.