Measurement-device-independent one-step quantum secure direct communication

The one-step quantum secure direct communication(QSDC)(Sci.Bull.67,367(2022))can effectively simplify QSDC’s operation and reduce message loss.For enhancing its security under practical experimental condition,we propose two measurement-device-independent(MDI)one-step QSDC protocols,which can resist all possible attacks from imperfect measurement devices.In both protocols,the communication parties prepare identical polarization-spatial-mode two-photon hyperentangled states and construct the hyperentanglement channel by hyperentanglement swapping.The first MDI one-step QSDC protocol adopts the nonlinear-optical complete hyperentanglement Bell state measurement(HBSM)to construct the hyperentanglement channel,while the second protocol adopts the linear-optical partial HBSM.Then,the parties encode the photons in the polarization degree of freedom and send them to the third party for the hyperentanglementassisted complete polarization Bell state measurement.Both protocols are unconditionally secure in theory.The simulation results show the MDI one-step QSDC protocol with complete HBSM attains the maximal communication distance of about354 km.Our MDI one-step QSDC protocols may have potential applications in the future quantum secure communication field.

Qualitative Simulation of Non-linear SISO System

The main target of Qualitative reasoning (QS) is to seek a computational theory in order to analog the human’s ability to acquisition and reasoning for physical common sense knowledge.Afte the publication of the first special volume of qualitative reasoning in Journal of AI at 1984,it has been admitted generally that there are three main methods of qualitative reasoning.Although the original goal of three methods are closed, all aim to the "Naive physics", the qualitative simulation method initiated by B.J.Kuipers now has already had a distance with the "Naive physics". It is being combined with sophisticated mathematical tools and becomes a powerful tool for describing the possible behaviors of incomplete systems, meanwhile, the application areas of qualitative simulation have been expanded from physical area to physiology, chemical engineering, automatic control, and economics, etc.. In this paper, we apply the QSIM algorithm to simulate a SISO system characterized by incomplete knowledge and use FPA method to analyze the qualitative stability of such system.