Quantum-State Tomography and Quantum Communication
The possibility to reconstruct a quasiprohability distribution1 from measured data attracted considerable interest in recent years. Following the proposal of Vogel and Risken2 the experimental feasibility of this scheme was demonstrated3. By measuring the rotated quadratures of a single-mode field we can reconstruct. the initial state to be measured, and in this way retrieve the full information eventually encoded in the initial state. In the case, we want, to employ a quantum system to transfer information, a. finite quantum system might be a better choice then an infinite-dimensional single mode system. In such a scheme an emitter (Alice) encodes the information on a finite quantum system and this is transferred to the observer (Bob). When Bob does not have at hand the decoding method he can still relay on the tomography approach. In the following we shortly demonstrate how this might work. Let, us note, that we do not claim. that the method is evesdropper safe.
KeywordsDensity Operator Wigner Function Quantum Communication Tomography Approach Spin Particle
- 2.K. Vogel. and H. Risken, Determination of quasiprobability distribution in terms of probability distributions for the rotated quadrature phase, Phys. Rev. A 40: 2487 (1989).Google Scholar