In quantum information theory, a quantum channel is a communication channel which can transmit quantum information, as well as classical information. An example of quantum information is the state of a qubit. An example of classical information is a text document transmitted over the internet.
More formally, quantum channels are completely positive, trace preserving maps between spaces of operators. In other words, a quantum channel is just a quantum operation viewed not merely as the reduced dynamics of a system but as a pipeline intended to carry quantum information.
Read more about Quantum Channel: Memoryless Quantum Channel, In The Experimental Setting, Channel Fidelity, Quantum Channel With Memory
Famous quotes containing the words quantum and/or channel:
“A personality is an indefinite quantum of traits which is subject to constant flux, change, and growth from the birth of the individual in the world to his death. A character, on the other hand, is a fixed and definite quantum of traits which, though it may be interpreted with slight differences from age to age and actor to actor, is nevertheless in its essentials forever fixed.”
—Hubert C. Heffner (1901–1985)
“There may sometimes be ungenerous attempts to keep a young man down; and they will succeed too, if he allows his mind to be diverted from its true channel to brood over the attempted injury. Cast about, and see if this feeling has not injured every person you have ever known to fall into it.”
—Abraham Lincoln (1809–1865)