Fighting Decoherence: Quantum Error-Correcting Codes
Sebastian Buhai · 2000
Abstract. The hereby paper presents an overview of the current interpretation of decoherence in quantum theory, at the same time firmly stating that decoherence can be successfully fought against by means of the quantum error-correcting codes developed in the recent years. While decoherence itself is but a natural transition from quantum to classical, explaining the so disputed quantum origins of the classical world, its effects have to be combated or severely diminished if revolutionary techniques such as quantum communication or quantum computation are to be ever implemented. We will argue and try to prove by reference to existing leading research papers that quantum error-correction codes are a viable solution for the decoherence problem in particular settings. As a clear-cut example we tackle the five-qubit quantum circuit described by Shor, DiVincenzo and Terhal. Full generalization is in our view a simple problem of time as the theory describing it exists already and is continuously revised by top scientists. In this sense the general QECC framework developed by Knill and Laflamme is thoroughly analyzed and commented upon. 1. Scene-Setting: Decoherence as Transition Concept between Quantum and Classical If we were to consider decoherence in its full generality