Tunnel junction based memristors as artificial synapses

Thomas A, Niehörster S, Fabretti S, et al. Tunnel junction based memristors as artificial synapses. Frontiers in Neuroscience. 2015;9: 241.We prepared magnesia, tantalum oxide and barium titanate based junction structures and investigated their memristive properties. The low amplitudes of the resistance change in these types of junctions are the major obstacle for their use. Here, we increased the amplitude of the resistance change from 10% up to 100%. Utilizing the memristive properties, we looked into the use of the junction structures as artificial synapses. We observed analogs of longterm potentiation, long-term depression and spike-time dependent plasticity in these simple two terminal devices. Finally, we suggest a possible pathway of these devices towards their integration in neuromorphic systems for storing analog synaptic weights and supporting the implementation of biologically plausible learning mechanisms