Magic state distillation is a method for creating more accurate quantum states from multiple noisy ones, which is important[1] for building fault tolerant quantum computers. It has also been linked[2] to quantum contextuality, a concept thought to contribute to quantum computers' power.[3]
The technique was first proposed by Emanuel Knill in 2004,[4]
and further analyzed by Sergey Bravyi and Alexei Kitaev the same year.[5]
Thanks to the Gottesman–Knill theorem, it is known that some quantum operations (operations in the Clifford group) can be perfectly simulated in polynomial time on a classical computer. In order to achieve universal quantum computation, a quantum computer must be able to perform operations outside this set. Magic state distillation achieves this, in principle, by concentrating the usefulness of imperfect resources, represented by mixed states, into states that are conducive for performing operations that are difficult to simulate classically.
A variety of qubit magic state distillation routines[6][7] and distillation routines for qubits[8][9][10] with various advantages have been proposed.