Classifying or predicting complex time-dependent signals is a challenging computational task. Reservoir computing (RC) is an efficient neuromorphic computing approach that is ideally suited to such tasks, and is typically implemented in software using a recurrent neural network (RNN) with fixed synaptic weights (the reservoir) connected to a single, trainable readout layer. However, more efficient implementations of RC are possible if the software RNN reservoir is substituted with a physical system with the correct properties, such as non-linear response to input signals and inherent memory [1].<br/>In this work, we exploit the chaotic and non-linear dynamics of a single magnetic domain wall (DW) trapped between two anti-notches in a Ni nanostrip as a hardware-based reservoir. We have modelled the structure (inset of Fig. 1) using both a simple 1D model and micromagnetic simulations with an oscillating field. As shown in Fig. 1, complex oscillatory dynamics over a range of field amplitudes are observed. A chaotic and multi-period regime occurs between 0.4 kA/m and 1.2 kA/m and a non-linear regime at higher fields. Thus, the DW oscillator can be used to transform an input magnetic field to the DW position output suitable for RC.<br/>A time-multiplexed input signal is injected into the DW oscillator by modulating the applied field magnitude, and we show how this approach allows the device to perform classification tasks as a reservoir.First, we demonstrate how the scaling to convert input data into applied fields affects the classification accuracy of the sine or square wave task, showing that the best recognition rate is obtained at the edge of a chaotic regime of oscillation (Fig.2). We also demonstrate that the DW oscillator can perform complex tasks, such as spoken digit recognition, and that coupling multiple DWs together enhances the computational capabilities of the reservoir. Our work opens new avenues for research into neuromorphic computing using nanomagnetic hardware.

![](https://assets.underline.io/uploads/markdown_image/1/image/b1c2f88ba8e32e54699a48e2fafd9388.jpg)

Bifurcation plot showing the DW position once per cycle for a given applied field using the 1D model. Inset: Schematic of the system.

![](https://assets.underline.io/uploads/markdown_image/1/image/7c99dd1e515fbc149d6687d21ac4a5b5.jpg)

Classification accuracy of the Sine-Square task over a range of field centre (H0) and field width (ΔH) values.


Neuromorphic computation with a single magnetic domain wall

In the Northern Ionian Sea, the Calabrian Accretionary Wedge (CAW) is facing directly the subducting Apula plate, mainly made of Mesozoic to Tertiary Carbonate Platform (Del Ben et al., 2010; Volpi et al., 2017). This contribution illuminates the structures and stratigraphic relationships between the frontal part of the orogenic belt, the foredeep and adjacent Apulian foreland. A detailed seismic facies analysis of four multichannel seismic profiles has been carried out to define the tectonic-sedimentary evolution of the study area but without exploration wells not available for these deep offshore area. Seismic interpretation allows to identify four main structural domains: the highly tectonized CAW; the narrow foredeep basin filled by a Pliocene-Holocene subhorizontal succession laying above buried normal faults; the massive carbonate succession of the Apulian Platform showing reef and carbonate platform margin facies; the layered succession of the Apulian Platform characterized by ‘'intra-platform'’ facies in the easternmost portion of the area. Three main regional unconformities with characteristic relationships with structural trends were recognized: i) the Messinian unconformity, related to a regional and significant erosion associated to paleokarst processes on the exposed Mesozoic Apulian Platform, is cut by an array of normal faults in the Apulian foreland and by thrust in the accretionary wedge; ii) the angular and erosive middle Pliocene Unconformity truncates the Lower Pliocene reflectors and is affected by normal faults in the foreland and by compressive tectonics in the CAW; iii) a Jurassic/Cretaceous unconformity in the Apulian foreland is marked by Cretaceous reflectors onlapping the Jurassic carbonate platform. The CAW is characterized by compressive tectonics with several fore-thrusts forming a leading imbricate fan system nearby the orogenic front. The Mesozoic Apulian platform is affected by active extensional tectonics driven by flexural bending since Lower Pliocene (Volpi et al., 2017; Maesano et al., 2020), that probably reactivated old normal faults related to the Permian-Triassic rifting stage. The structural map shows that transpressive and positive inversion tectonics is a common deformational style in the central sector of the foreland, suggesting that the Apulia plate is already part of the Calabrian/Hellenic belt. According to these observations, the compressive tectonics affecting the Apula plate is interpreted as related to shortening processes of both the CAW and Hellenic wedge whose interference plays an important role in defining the tectonic-stratigraphic evolution of the Apula Plate in the Northern Ionian Sea.

The response of the Apula plate to the advancing Calabrian and Hellenic wedges (Northern Ionian Sea): implications for subduction processes and tectono-stratigraphic evolution

Predicting avalanches in granular materials from 'vibrational' modes

Multiscale modeling of granular media for geomechanics and beyond

We propose an aging degradation suppression scheme at constant performance by controlling supply voltage and body bias for an FDSOI device. Reducing supply voltage while increasing body bias can maintain performance and suppress dynamic power and aging degradation caused by BTI. From measurement results of ring oscillators in a 65 nm    FDSOI, NBTI- and PBTI-induced degradations can be reduced by 29% and 10% at 1.5 V supply voltage and 0.15 V forward body bias paying the penalty of 2x leak power increase.

An Aging Degradation Suppression Scheme at Constant Performance by Controlling Supply Voltage and Body Bias in a 65 nm Fully-Depleted Silicon-On-Insulator Process

A constant current stress scheme is implemented for endurance study on OTS-PCM devices for the first time. It provides a feasible method to estimate the read/write endurance for cross-point PCM products, which can save testing time for chips qualification.          

Endurance Evaluation on OTS-PCM Device using Constant Current Stress Scheme

Endurance ~ 1012 cycling of ferroelectric (FE) and antiferroelectric (AFE) HfZrO2 (HZO) capacitors are achieved experimentally by adjusting the programming pulse width (tp). The correlation between switching polarization (△P) and fatigue behavior of high endurance is discussed. For long tp (= 1 µs), AFE exhibits excellent endurance with &gt; 1010 cycles as compared with FE ~ 109 cycles. With shortening tP, the endurances of FE and AFE are significantly improved. There is no significant degradation until &gt; 1011 cycling is observed for FE with tp=20ns. 

Correlation between Access Polarization and High Endurance (~ 1012 cycling) of Ferroelectric and Anti-Ferroelectric HfZrO2

This paper investigates the
characterization of charge trapping and its modelling on hafnia-based
ferroelectric field effect transistors (FeFETs). Defect characterization on
MOSFETs can be done by studying threshold voltage shifts (DVth) as a function of charging and
relaxation times. At positive gate voltages one expects electron trapping in
the gate oxide to result in a positive shift of the threshold voltage (Vth). However, on a FeFET those conditions
will induce polarization changes in the gate oxide leading to a negative Vth-shift, complicating the characterization
of defect levels. We aim to alleviate these difficulties by modelling the
polarization and trapping in FeFETs over a wide range of timescales, suitable
for defect characterization. We demonstrate quantitative agreement on long
timescales with a static polarization model while a time-dependent polarization
model can be used for qualitative agreement over a wide range of times from 30
ms to 2 ks.

Trap-polarization interaction during low-field trap characterization on hafnia-based ferroelectric gatestacks

The self-protection of SOI RF switches is presented in this paper. TLP ESD test results show that the ESD protection performance of SOI RF switches is impacted by various parameters, including switch array gate channel length, finger width, finger number, and RF switch stack number. The physics of the SOI RF switch ESD protection mechanism is also studied by comparing TLP ESD test results from SOI RF switch splits and other ESD protection structures. It is concluded that the SOI RF switch self-protection process during ESD transients contains two mechanisms: NMOS channel conduction triggered by gate coupling effect and parasitic bipolar turning on. 

Characterization and Analysis of RF Switches in SOI Technology for ESD Protection

In this paper, a high holding voltage dual-directional silicon-controlled rectifier (SCR) with an embedded shunt path (HVDDSCR-ESP) for high-voltage I/O electrostatic discharge (ESD) protection is proposed. Based on the 0.13-μm BCD process, multi-current pulses that mimic the transmission line pulse (TLP) are applied to devices by using Sentaurus-TCAD. The results reveal that the proposed structure, compared with the conventional low-trigger dual directional SCR (LTDDSCR), has adjustable high holding voltage and good ESD robustness. In addition, the working mechanisms are also investigated, and the proposed device as the ESD cell is beneficial for the 12V applications and has no risk of latch-up.

A Novel Latch-Up-Immune DDSCR Used for 12 V Applications

In this work an implicit finite element model of a Printed Circuit Board (PCB), connectors, and stiffener is developed. The effect of several parameters on the strain distribution on the board was analyzed. The PCB was bolted to an aluminum stiffener. The simulation went through several steps to consider the effect of the solder reflow process as well as bolt pretension forces and plug-in forces of the connectors. Based on the simulation, board warpage and bolt pretension forces had significant effect on board strain. 

Numerical Simulation and characterization of PCB Warpage

Adhesion-Limit in Refractory Transition Metal (Mo) Contact Relay Operation at 300 °C— Avoiding Overestimation for Modern ICs

Underline digital video library

Neuromorphic computation with a single magnetic domain wall

The response of the Apula plate to the advancing Calabrian and Hellenic wedges (Northern Ionian Sea): implications for subduction processes and tectono-stratigraphic evolution

Predicting avalanches in granular materials from 'vibrational' modes

Multiscale modeling of granular media for geomechanics and beyond

An Aging Degradation Suppression Scheme at Constant Performance by Controlling Supply Voltage and Body Bias in a 65 nm Fully-Depleted Silicon-On-Insulator Process

Endurance Evaluation on OTS-PCM Device using Constant Current Stress Scheme

Correlation between Access Polarization and High Endurance (~ 1012 cycling) of Ferroelectric and Anti-Ferroelectric HfZrO2

Trap-polarization interaction during low-field trap characterization on hafnia-based ferroelectric gatestacks

Characterization and Analysis of RF Switches in SOI Technology for ESD Protection

A Novel Latch-Up-Immune DDSCR Used for 12 V Applications

Numerical Simulation and characterization of PCB Warpage

Adhesion-Limit in Refractory Transition Metal (Mo) Contact Relay Operation at 300 °C— Avoiding Implicated Overestimation for Modern ICs

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