What is a quantum ?
Subfields include : Quantum computing , which deals on the one hand with the question how and whether one can build a quantum computer and on the other hand , algorithms that harness its power ( see quantum algorithm ) Quantum complexity theory Quantum cryptography and its generalization , quantum communication Quantum error correction Quantum communication complexity Quantum entanglement , as seen from an information - theoretic point of view Quantum dense coding Quantum teleportation is a well - known quantum information processing operation , which can be used to move any arbitrary quantum state from one particle ( at one location ) to another .