A Statistical Study of Resistive Switching Parameters in Au/Ta/ZrO2(Y)/Ta2O5/TiN/Ti Memristive Devices

The authors acknowledge the Consejería de Conocimiento, Investigación y Universidad, Junta de Andalucía (Spain), European Regional Development Fund (ERDF) under projects A-TIC-117-UGR18, B-TIC-624-UGR20, and IE2017-5414. Support from the Government of the Russian Federation under Megagrant Program (agreement no. 074-02-2018-330 (2)) and the Ministry of Science and Higher Education of the Russian Federation under “Priority-2030” Academic Excellence Program of the Lobachevsky State University of Nizhny Novgorod (N-466-99_2021- 2023) is also acknowledged. Memristive devices were designed in the frame of the scientific program of the National Center for Physics and Mathematics (project “Artificial intelligence and big data in technical, industrial, natural and social systems”).Variability is an inherent property of memristive devices based on the switching of resistance in a simple metal–oxide–metal structure compatible with the standard complementary metal–oxide–semiconductor fabrication process. For each specific structure, the variability should be measured and assessed as both the negative and positive factors for different applications of memristive devices. In this report, it is shown how this variability can be extracted and analyzed for such main parameters of resistive switching as the set and reset voltages/cur- rents and how it depends on the methodology used and experimental conditions. The obtained results should be taken into account in the design and predictive simulation of memristive devices and circuits.Consejería de Conocimiento, Investigación y Universidad, Junta de Andalucía (Spain), European Regional Development Fund (ERDF) under projects A-TIC-117-UGR18, B-TIC-624-UGR20, and IE2017-5414Government of the Russian Federation under Megagrant Program (agreement no. 074-02-2018-330 (2))Ministry of Science and Higher Education of the Russian Federation under “Priority-2030” Academic Excellence Program of the Lobachevsky State University of Nizhny Novgorod (N-466-99_2021- 2023

Astrocyte control bursting mode of spiking neuron network with memristor-implemented plasticity

A mathematical model of a spiking neuron network accompanied by astrocytes is considered. The network is composed of excitatory and inhibitory neurons with synaptic connections supplied by a memristor-based model of plasticity. Another mechanism for changing the synaptic connections involves astrocytic regulations using the concept of tripartite synapses. In the absence of memristor-based plasticity, the connections between these neurons drive the network dynamics into a burst mode, as observed in many experimental neurobiological studies when investigating living networks in neuronal cultures. The memristive plasticity implementing synaptic plasticity in inhibitory synapses results in a shift in network dynamics towards an asynchronous mode. Next,it is found that accounting for astrocytic regulation in glutamatergic excitatory synapses enable the restoration of 'normal' burst dynamics. The conditions and parameters of such astrocytic regulation's impact on burst dynamics established

Spatial computing in structured spiking neural networks with a robotic embodiment

One of the challenges of modern neuroscience is creating a "living computer" based on neural networks grown in vitro. Such an artificial device is supposed to perform neurocomputational tasks and interact with the environment when embodied in a robot. Recent studies have identified the most critical challenge, the search for a neural network architecture to implement associative learning. This work proposes a model of modular architecture with spiking neural networks connected by unidirectional couplings. We show that the model enables training a neuro-robot according to Pavlovian conditioning. The robot's performance in obstacle avoidance depends on the ratio of the weights in inter-network couplings. We show that besides STDP, critical factors for successful learning are synaptic and neuronal competitions. We use the recently discovered shortest path rule to implement the synaptic competition. This method is ready for experimental testing. Strong inhibitory couplings implement the neuronal competition in the subnetwork responsible for the unconditional response. Empirical testing of this approach requires a technique for growing neural networks with a given ratio of excitatory and inhibitory neurons not available yet. An alternative is building a hybrid system with in vitro neural networks coupled through hardware memristive connections

Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV

Peer reviewe

Specificity of formation of creative activity skills in studio theatre: competency-based approach

This article presents the experimental results of analysis of efficiency of teaching methods aimed at formation of creative activity skills of future actors during training in studio theatre. In the course of the research, psychological and pedagogical theories of formation of creative activity skills were studied; on the basis of experiments, the efficiency of specially developed methods aimed at formation of creative activity skills was proved. These are the methods of development of imagination and thinking, actor abilities, expansion of emotional sphere, worldview and experience of actors in the area of perception of arts pieces, and scenic practice in working on role and stage performance. The authors have systematized the skills of theatrical performance and highlighted as the most meaningful the skills of artistry, scenic mastery, creation of new images or actions, application of various means of stage arts, preparation and performance of stage pieces of various genres, execution of professional functions of actor, director, scriptwriter. Practical value of the work is in obtaining of new scientific data as well as formulation of recommendations regarding the process of formation and development of creative activity skills of students during training in studio theatre

The carbene transfer to strong Lewis acids: copper is better than silver

A new convenient approach to the synthesis of useful N-heterocyclic carbene complexes of group 13 metals was successfully developed. We demonstrate that air-stable copper(i) diaminocarbene complexes are excellent carbene transfer reagents for the synthesis of (IMes or IPr)MCl3 with high yields (M = Al, Ga). Use of this simple method allowed for the first time to obtain (IPr)AlCl3, inaccessible via a free carbene route. In contrast to copper complexes, under the same conditions the more commonly used silver analog (IPr)AgCl reacts with MCl3 (M = Al, Ga, In) yielding only the homoleptic cationic complexes [(IPr)(2)Ag]+MCl4-

Silicon-Compatible Memristive Devices Tailored by Laser and Thermal Treatments

Nowadays, memristors are of considerable interest to researchers and engineers due to the promise they hold for the creation of power-efficient memristor-based information or computing systems. In particular, this refers to memristive devices based on the resistive switching phenomenon, which in most cases are fabricated in the form of metal–insulator–metal structures. At the same time, the demand for compatibility with the standard fabrication process of complementary metal–oxide semiconductors makes it relevant from a practical point of view to fabricate memristive devices directly on a silicon or SOI (silicon on insulator) substrate. Here we have investigated the electrical characteristics and resistive switching of SiOx- and SiNx-based memristors fabricated on SOI substrates and subjected to additional laser treatment and thermal treatment. The investigated memristors do not require electroforming and demonstrate a synaptic type of resistive switching. It is found that the parameters of resistive switching of SiOx- and SiNx-based memristors on SOI substrates are remarkably improved. In particular, the laser treatment gives rise to a significant increase in the hysteresis loop in I–V curves of SiNx-based memristors. Moreover, for SiOx-based memristors, the thermal treatment used after the laser treatment produces a notable decrease in the resistive switching voltage

Effect of Si+ ion implantation in α-Ga2O3 films on their gas sensitivity

The effect of the Si+ ion implantation on the gas-sensing properties of single-crystal (0001) α-Ga2O3 films grown by halide vapor phase epitaxy (HVPE) has been studied. It is established that irradiation with a dose of 8 × 1012– 8 × 1015 cm−2 at an energy of 100 keV followed by postimplantation annealing increases the response of α-Ga2O3 films to 3 vol% of H2 by 43 times at 400 ◦C, reduces the response time by a factor of 6, and expands the operating temperature range down to 30 ◦C. In addition, α-Ga2O3 layers irradiated with a Si+ ion dose of 8 × 1013–8 × 1015 cm−2 demonstrate high sensitivity to CO and NH3 gases. The mechanism of Si+ ion irradiationeffect on the gas-sensingproperties of α-Ga2O3 structures is proposed