Percolation threshold enables optical resistive‐memory switching and light‐tuneable synaptic learning in segregated nanocomposites

An optical memristor where the electrical resistance memory depends on the history of both the current flowing through the device and the irradiance of incident light onto it is demonstrated. It is based on a nanocomposite consisting of functionalized gold nanoparticles in an optically active azobenzene polymer matrix. The composite has an extremely low percolation threshold of 0.04% by volume for conductivity because of the aggregation of the conducting nanoparticles into filamentary nanochannels. Optical irradiation results in photomechanical switching through expansion of the thin film from above to below the percolation threshold, giving a large LOW/HIGH resistance ratio of 103. The device acts as an artificial synapse, the conductivity or plasticity of which can be independently modulated, either electrically or optically, to enable tunable and reconfigurable synaptic circuits for brain‐inspired artificial intelligent or visual memory arrays. The lifetime of the resistive‐memory states is also optically controllable, which enables spatial modulation of long‐ and short‐term memory

Multilevel Resistance Switching and Enhanced Spin Transition Temperature in Single and Double Molecule Spin Crossover Nanogap Devices

Spin crossover (SCO) molecules are promising bi-stable magnetic switches with applications in molecular spintronics. However, little is known about the switching effects of a single SCO molecule when it is confined between two metal electrodes. Here we examine the switching properties of a [Fe(III)(EtOSalPet )(NCS)] SCO molecule that is specifically tailored for surface deposition and binding to only one gold electrode in a nanogap device. Temperature dependent conductivity measurements on SCO molecule containing electromigrated gold break junctions show voltage independent telegraphic-like switching between two resistance states at temperature below 200 K. The transition temperature is very different from the transition temperature of 83 K that occurs in a bulk film of the same material. This indicates that the bulk, co-operative SCO phenomenon is no longer preserved for a single molecule and that the surface interaction drastically increases the temperature of the SCO phenomenon. Another key finding of this work is that some devices show switching between multiple resistance levels. We propose that in this case, two SCO molecules are present within the nanogap with both participating in the electronic transport and switching

The multidimensional impacts of external price shocks on macroeconomic variables: Malaysian experiences from recession to economic instability

The 2008 to 2009 global external price shocks on foods and oil exert worldwide impacts on production, expenditure pattern, trade, welfare, internal resource allocation and ultimate impacts diverted to global recession, Malaysia is not an exception. Centering the world's (2008 to 2009) oil and food price catastrophe, here we investigate Malaysian experiences from recession to economic instability. An applied computable general equilibrium model is utilized in our study to simulate the Malaysian economic impacts by three scenarios. First is food import price increase by 20% (Scenario 1), second is the oil price catastrophe by 40% (Scenario 2) and finally a scenario that combines Scenarios 1 and 2 simultaneously (Scenario 3). Our results depict the multidimensional impacts on major macroeconomic indicators from recession to economic instability. Our results indicate that, price catastrophe either in Scenario 1 or 2, or in Scenario 3, depress overall Malaysian domestic outputs and exports. Reduced output also reduces employment, thus causing a fall in household's income. Overall imports also decreased by 0.2, 1.5, and 1.7% respectively, in all scenarios that specify consumers can afford less quantity of both domestic and imported goods; is the clear indication of recession and economic instability. Our study can be a message to policy makers, who are considering recession and trade policy together