An epitaxial perovskite as a compact neuristor: electrical self-oscillations in TbMnO₃ thin films

Abstract

Developing materials that can lead to compact versions of artificial neurons (neuristors) and synapses (memristors) is the main aspiration of the nascent neuromorphic materials research field. Oscillating circuits are interesting as neuristors, as they emulate the firing of action potentials. Here we present room-temperature self-oscillating devices fabricated from epitaxial thin films of semiconducting TbMnO3. We show that the Negative Differential Resistance (NDR) regime observed in these devices, orginates from transitions across the electronic band gap of the semiconductor. The intrinsic nature of the mechanism governing the oscillations gives rise to a high degree of control and repeatability. Obtaining such properties in an epitaxial perovskite oxide opens the way towards combining self-oscillating properties with those of other piezoelectric, ferroelectric, or magnetic perovskite oxides in order to achieve hybrid neuristor-memristor functionality in compact heterostructures.

Dynamics of Voltage-Driven Self-Sustained Oscillations in NdNiO3 Neuristors

“…These curves show a non-linear dependence of frequency with voltage. Although our experiments did not reflect this non-linearity clearly, it was observed experimentally in other threshold memristor systems …”

“…Although our experiments did not reflect this non-linearity clearly, it was observed experimentally in other threshold memristor systems. 43 The non-dependence of current oscillation amplitude on the applied voltage was also observed experimentally by us as well as other researchers on different Mott insulating systems. 35 However, unlike previous models, our simple electrothermal model precisely captures this behavior (further explanation is furnished in section D of Supporting Information, Figures S5 and S6).…”

Photoinduced Negative Differential Resistivity and Gunn Oscillations in SrTiO3

“…The Sshape or the current-controlled NDR is generally based on impact ionization, filamentary conduction generated by the local phase change or soft breakdown. [14] The IV characteristics shown here belong to the second type, the voltage controlled negative resistance, generating an N-type IV characteristics. [15] This type of NDR is usually produced in classical bulk semiconductors by a transferred-electron effect or in special quantum tunnel devices such as Esaki or resonant tunneling diodes.…”

“…The S‐shape or the current‐controlled NDR is generally based on impact ionization, filamentary conduction generated by the local phase change or soft breakdown. [ 14 ]…”

Frequency Modulation Based Long‐Wave Infrared Detection and Imaging at Room Temperature

“…While a LWIR detector utilizing the NDR of PCM in conjunction with FM-based detection has yet to be reported, prior research has demonstrated the successful creation of self-oscillators with NDR using various PCM, such as metal oxides and 2D materials. [26][27][28][29] Consequently, for the purpose of presenting a general detection scheme, we use the terms PCM and VO 2 interchangeably in the following description. Our room-temperature LWIR detector exhibits a noise equivalent power (NEP) of less than 3 pW • Hz −1/2 , response time ≈2.96 ms and a high detectivity of the order of 10 9 comparable to cryogenically cooled LWIR detectors.…”