2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/213683A geometric interpretation for the A-fidelity between two states of a qubit system is presented, which leads to an upper bound of the Bures fidelity. The metrics defined based on the A-fidelity are studied by numerical method. An alternative generalization of the A-fidelity, which has the same geometric picture, to a $N$-state quantum system is also discussed.4 pages, 1 figure. Phys. Rev. AQuantum Physicstext