Quantum computing is a relatively new discipline involving the intersection of the fields of quantum physics and computer science.
In a quantum state, particles achieve a natural phenomenon known as superposition; which involves them existing in multiple magnetic states by spinning in two different positions at once,thus forming the basis of a quantum computer.
Unlike classical computing,where data is encoded in bit(binary digit) ,which can either exist as a 0 or a 1,qubit(quantum bit),which refers to how data is encoded in quantum computing can exist as a 0 or a 1 or both simultaneously (or more simply an infinite number of superpositions of states) making it ideal for solving certain calculations that will take eons for classical computers.
Current quantum computing solutions from D-Wave,Google,NASA,IBM and hopefully Microsoft will pioneer the development of quantum computers which are now complex by design,limited to about 512 or 1000+ qubits (referring to D-Wave 2 and D-Wave 2x respectively) and require cryogenically close to absolute zero to operate; all pointing to how different quantum computers are from conventional computers,even though they are quite similar theoretically in non-deterministic and probabilistic computing.
Research spanning from quantum mechanics,quantum electrodynamics(QED),quantum chromodynamics(QCD) and the elusive quantum entanglement remains imperative to the development of a practical quantum computer.
In particle physics, Quantum electrodynamics (QED) is the relativistic quantum field theory of electrodynamics. In essence, it describes how light and matter interact and is the first theory where full agreement between quantum mechanics and special relativity is achieved.
In theoretical physics, Quantum chromodynamics (QCD) is the theory of strong interactions,a fundamental force describing the interactions between quarks and gluons which make up hadrons such as the proton, neutron and pion.
Quantum entanglement is a physical phenomenon that occurs when pairs or groups of particles are generated or interact in ways such that the quantum state of each particle cannot be described independently of the others, even when the particles are separated by a large distance—instead, a quantum state must be described for the system as a whole.