Performance characterization of pauli channels assisted by indefinite causal order and post-measurement

© Rinton Press.Indefinite causal order has introduced disruptive procedures to improve the fidelity of quantum communication by introducing the superposition of orders on a set of quantum channels. It has been applied to several well characterized quantum channels as depo-larizing, dephasing and teleportation. This work analyses the behavior of a parametric quantum channel for single qubits expressed in the form of Pauli channels. Combina-torics lets to obtain affordable formulas for the analysis of the output state of the channel when it goes through a certain imperfect quantum communication channel when it is deployed as a redundant application of it under indefinite causal order. In addition, the process exploits post-measurement on the associated control to select certain com-ponents of transmission. Then, the fidelity of such outputs is analysed to characterize the generic channel in terms of its parameters. As a result, we get notable enhancement in the transmission of information for well characterized channels due to the combined process: indefinite causal order plus post-measurement.