Quantum computing uses quantum-mechanical phenomena such as superposition and entanglement to develop quantum computers which are able to perform certain tasks in a fraction of time compared to traditional computers.
Quantum Computing is the newest field of computer science and develops quantum computers that use quantum-mechanical phenomena as the basis of quantum computer’s performance. Quantum computers are much faster than traditional computers due to the ability of performing several tasks at the same time and offer many chances for data base analytics, simulation and internet security (cryptography).
Every computer consists of millions of transistors that act as data processors. With an increasing number of transistors, a computer’s computing power increases accordingly (Moore’s law). Transistors work after an easy principle of either blocking or allowing information to come through (manipulation gates). This information is made up of bits, which can be set to either 1 or 0. The more bits are combined the more complex the information becomes and the more transistors and computing power is needed. Quantum computers as the newest invention in computer science use so called “qubits” instead of normal bits. Qubits are photons in a magnetic field that can be, depending on their horizontal or vertical polarization 1 and 0 at the same time. This principle is called superposition. As long as the qubit is unobserved, it is in its superposition of either 1 or 0, but the moment its value is tested or manipulated, e.g. by a filter or a quantum gate it collapses into one state.
The power of quantum computers lies in the possession and manipulation of all qubits at the same time by using those quantum gates that can manipulate its superpositions.
As a result data processing is no more following a step by step procedure but a processing of all data at the same time.
This brings enormous advantages for data base searching since no more tests of each single entry is needed but it can all be tested at the same time which shrinks the searching time to a completely new level. Another field of application is IT security. For traditional computers it would take years to get a secret key out of a public key (public-key cryptography) but quantum computers can find the correlation between the keys in a few minutes due to their enormous computing power.
The field of quantum computing is a very young research field and only a few quantum computers have been developed so far. It is very complicated to operate them since their temperature has to be a fraction above 0 degrees which makes its operation very costly and not profitable yet. Furthermore, their use makes only sense in fields where a huge data load has to be processed, for normal offices the use a traditional computer is still more effective.
Literature: Chubb, Eskandarian, Harizanov (2016): Logic and algebraic structures in quantum computing. Cambridge University Press