# Another look at the optimal Bayes cost in the binary decision problem - Quantum Physics

Another look at the optimal Bayes cost in the binary decision problem - Quantum Physics - Download this document for free, or read online. Document in PDF available to download.

Abstract: The problem of quantum state discrimination between two wave functions of aparticle in a square well potential is considered. The optimal minimum-errorprobability for the state discrimination is known to be given by the Helstrombound. A new strategy is introduced here whereby the square well is compressedisoenergetically, modifying the wave-functions. The new contracted chamber isthen probed using the conventional optimal strategy, and the error probabilityis calculated. It is shown that in some cases the Helstrom bound can beviolated, i.e. the state discrimination can be realized with a smaller errorprobability.

Author: ** Bernhard K. Meister**

Source: https://arxiv.org/