Viewing Air Battle Management Through the Lens of Interdependence

Recent work has shown the importance of understanding and supporting interdependence relationships among agents engaging in complex, joint activities. Building on the Coactive Design Method of Johnson, the goal of this research was to determine the impact of providing operators with real-time information of team interdependencies. It was hypothesized that allowing operators to focus on maximizing the opportunities for team synergy would result in better planning in a dynamic environment. Operators in the Air Battle Management field used a decision aid that provided information on team interdependence during three combat scenarios. Effectiveness of the decision aid was measured by expert assessment of the operator’s decisions. The results of this study could help to inform future training aids and interface design for command and control systems

Record spintronic harvesting of thermal fluctuations using paramagnetic molecular centers

Experiments and theory are reexamining how the laws of thermodynamics are expressed in a quantum world. Most quantum thermodynamics research is performed at sub-Kelvin temperatures to prevent thermal fluctuations from smearing the quantum engine's discrete energy levels that mediate the asymmetric shuffling of electrons between the electrodes. Meanwhile, several groups report that building an electron-spin based implementation by placing the discrete spin states of paramagnetic centers between ferromagnetic electrodes can not only overcome this drawback, but also induce a net electrical power output despite an apparent thermal equilibrium. We illustrate this thermodynamics conundrum through measurements on several devices of large output power, which endures beyond room temperature. We've inserted the Co paramagnetic center in Co phthalocyanine molecules between electron spin-selecting Fe/C60 interfaces within vertical molecular nanojunctions. We observe output power as high as 450nW(24nW) at 40K(360K), which leapfrogs previous results, as well as classical spintronic energy harvesting strategies involving a thermal gradient. Our data links magnetic correlations between the fluctuating paramagnetic centers and output power. This device class also behaves as a spintronically controlled switch of current flow, and of its direction. We discuss the conceptual challenges raised by these measurements. Better understanding the phenomenon and further developing this technology could help accelerate the transition to clean energy. Abstract (150 words) Several experiments have suggested that building a quantum engine using the electron spin enables the harvesting of thermal fluctuations on paramagnetic centers even though the device is at thermal equilibrium. We illustrate this thermodynamics conundrum through measurements on several devices of large output power, which endures beyond room temperature. We've inserted the Co paramagnetic center in Co phthalocyanine molecules between electron spin-selecting Fe/C60 interfaces within vertical molecular nanojunctions. We observe output power as high as 450nW(24nW) at 40K(360K), which leapfrogs previous results, as well as classical spintronic energy harvesting strategies involving a thermal gradient. Our data links magnetic correlations between the fluctuating paramagnetic centers and output power. This device class also behaves as a spintronically controlled switch of current flow, and of its direction. We discuss th

Localized states in advanced dielectrics from the vantage of spin- and symmetry-polarized tunnelling across MgO

Équipe 101 : Nanomagnétisme et électronique de spinInternational audienceResearch on advanced materials such as multiferroic perovskites underscores promising applications, yet studies on these materials rarely address the impact of defects on the nominally expected materials property. Here, we revisit the comparatively simple oxide MgO as the model material system for spin-polarized solid-state tunnelling studies. We present a defect-mediated tunnelling potential landscape of localized states owing to explicitly identified defect species, against which we examine the bias and temperature dependence of magnetotransport. By mixing symmetry-resolved transport channels, a localized state may alter the effective barrier height for symmetry-resolved charge carriers, such that tunnelling magnetoresistance decreases most with increasing temperature when that state is addressed electrically. Thermal excitation promotes an occupancy switchover from the ground to the excited state of a defect, which impacts these magnetotransport characteristics. We thus resolve contradictions between experiment and theory in this otherwise canonical spintronics system, and propose a new perspective on defects in dielectrics

Localized states in advanced dielectrics from the vantage of spin- and symmetry-polarized tunnelling across MgO

Research on advanced materials such as multiferroic perovskites underscores promising applications, yet studies on these materials rarely address the impact of defects on the nominally expected materials property. Here, we revisit the comparatively simple oxide MgO as the model material system for spin-polarized solid-state tunnelling studies. We present a defect-mediated tunnelling potential landscape of localized states owing to explicitly identified defect species, against which we examine the bias and temperature dependence of magnetotransport. By mixing symmetry-resolved transport channels, a localized state may alter the effective barrier height for symmetry-resolved charge carriers, such that tunnelling magnetoresistance decreases most with increasing temperature when that state is addressed electrically. Thermal excitation promotes an occupancy switchover from the ground to the excited state of a defect, which impacts these magnetotransport characteristics. We thus resolve contradictions between experiment and theory in this otherwise canonical spintronics system, and propose a new perspective on defects in dielectrics