Rényi Entropy, Signed Probabilities, and the Qubit
arXiv:2010.02111 · doi:10.3390/e24101412
Abstract
The states of the qubit, the basic unit of quantum information, are positive semi-definite Hermitian matrices with trace 1. We contribute to the program to axiomatize quantum mechanics by characterizing these states in terms of an entropic uncertainty principle formulated on an eight-point phase space. We do this by employing Rényi entropy (a generalization of Shannon entropy) suitably defined for the signed phase-space probability distributions that arise in representing quantum states.
13 pages, 1 figure