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Tunnel junction based memristors as artificial synapses.

Thomas A, Niehörster S, Fabretti S, Shepheard N, Kuschel O, Küpper K, Wollschläger J, Krzysteczko P, Chicca E - Front Neurosci (2015)

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Thin Films and Physics of Nanostructures, Bielefeld University Bielefeld, Germany ; IFW Dresden, Institute for Metallic Materials Dresden, Germany.

ABSTRACT
We prepared magnesia, tantalum oxide, and barium titanate based tunnel 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 long-term potentiation, long-term depression and spike-time dependent plasticity in these simple two terminal devices. Finally, we suggest a possible pathway of these devices toward their integration in neuromorphic systems for storing analog synaptic weights and supporting the implementation of biologically plausible learning mechanisms.

No MeSH data available.


Related in: MedlinePlus

Analogs of long-term potentiation and long-term depression of a Ta-O based tunnel junction. Positive voltage pulses are depicted in green, negative voltage pulses in blue. The pulse voltage was ±600 mV in all cases.
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Figure 7: Analogs of long-term potentiation and long-term depression of a Ta-O based tunnel junction. Positive voltage pulses are depicted in green, negative voltage pulses in blue. The pulse voltage was ±600 mV in all cases.

Mentions: Furthermore, we are able to reach more than two states in a Ta-O based tunnel junctions, as shown in Figure 7. We generate the resistance steps by applying a voltage of ±600 mV for 15 s. The resulting resistance levels are measured with a voltage of 10 mV for 180 s. The first three positive (green) voltage pulses increase the resistance while the last (blue) negative pulse decreases it. We can observe the analog of long-term depression and long-term potentiation in Ta-O based junctions, and we have increased the signal by more than a factor of 10 compared to 10% resistance change in MgO based systems. This could emulate the synaptic weight in a neuromorphic chip, and a possible future implementation is suggested in the fifth section.


Tunnel junction based memristors as artificial synapses.

Thomas A, Niehörster S, Fabretti S, Shepheard N, Kuschel O, Küpper K, Wollschläger J, Krzysteczko P, Chicca E - Front Neurosci (2015)

Analogs of long-term potentiation and long-term depression of a Ta-O based tunnel junction. Positive voltage pulses are depicted in green, negative voltage pulses in blue. The pulse voltage was ±600 mV in all cases.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493388&req=5

Figure 7: Analogs of long-term potentiation and long-term depression of a Ta-O based tunnel junction. Positive voltage pulses are depicted in green, negative voltage pulses in blue. The pulse voltage was ±600 mV in all cases.
Mentions: Furthermore, we are able to reach more than two states in a Ta-O based tunnel junctions, as shown in Figure 7. We generate the resistance steps by applying a voltage of ±600 mV for 15 s. The resulting resistance levels are measured with a voltage of 10 mV for 180 s. The first three positive (green) voltage pulses increase the resistance while the last (blue) negative pulse decreases it. We can observe the analog of long-term depression and long-term potentiation in Ta-O based junctions, and we have increased the signal by more than a factor of 10 compared to 10% resistance change in MgO based systems. This could emulate the synaptic weight in a neuromorphic chip, and a possible future implementation is suggested in the fifth section.

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Thin Films and Physics of Nanostructures, Bielefeld University Bielefeld, Germany ; IFW Dresden, Institute for Metallic Materials Dresden, Germany.

ABSTRACT
We prepared magnesia, tantalum oxide, and barium titanate based tunnel 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 long-term potentiation, long-term depression and spike-time dependent plasticity in these simple two terminal devices. Finally, we suggest a possible pathway of these devices toward their integration in neuromorphic systems for storing analog synaptic weights and supporting the implementation of biologically plausible learning mechanisms.

No MeSH data available.


Related in: MedlinePlus