Selma Amara

• PhD
• PostDoc Position at King Abdullah University of Science and Technology

Smart mobility refers to optimizing transportation and communications to integrate new safety, efficiency, sustainability , and air quality standards. It interrelates various solutions, including improved health due to better air quality, less traffic congestion, and fewer victims in road accidents. However, the reliability and cybersecurity aspect...

In the wireless body area network (WBAN), radio propagations from devices that communicate with the human body are very complex and distinctive compared to other environments. As we know, the human body is a lossy channel that significantly attenuates the propagation of electromagnetic waves (EMW). Therefore, channel models are critical in evaluati...

Solid and liquid particles in the atmosphere, referred to as airborne particulate matter (PM), have been rising significantly over the past two decades. Exposure to PM carries significant health risks such as lungs damage, heart disease, cancer, and death. PM 2.5 is a subgroup of PM particles that are smaller than 2.5 µm and is a major concern as i...

Various hardware security concerns, such as hardware Trojans and IP piracy, have sparked studies in the security field employing alternatives to CMOS chips. Spintronic devices are among the most-promising alternatives to CMOS devices for applications that need low power consumption, non-volatility, and ease of integration with silicon substrates. T...

In recent years, discovering various vulnerabilities in the IC supply chain has raised security concerns in electronic systems. Recent research has proposed numerous attack and defense mechanisms involving various nanoelectronic devices. Spintronic devices are a viable choice among various nanoelectronic devices because of their non-volatility, eas...

The globalization of the Integrated Circuits supply chain has increased threats from untrusted entities involved in the process. Several mechanisms, such as logic locking, watermarking and split manufacturing, are widely used to ensure hardware security. This study describes a novel method for creating hardware watermarks inspired by finite-state m...

With the rapid interest in exploiting the advantages of beyond CMOS devices in various applications, we explore, in this work, voltage-gated spin-orbit torque-assisted magnetic tunnel junction (VGSOT-MTJ) based on the Verilog-A behavioral model to design a possible logic locking system for hardware security. The VGSOT MTJ can switch without needing...

This work explores spin-orbit torque (SOT) assisted magnetic tunnel junction (MTJ) as a potential candidate for designing sneaky hardware Trojan (HT). The type of payload targeted is IC malfunction using an externally triggered activation mechanism with an external magnetic field. To make it sneakier, we designed the Trojan to have sufficient toler...

Emerging spintronics devices in recent research have received much interest in various fields. Their unique physical aspects are being explored to keep Moore’s law alive. Therefore, the hardware security aspects of system-on-a-chip (SoC) designs using spintronics devices becomes important. Magnetic tunnel junctions (MTJ) are a potential candidate i...

Today’s technology demands compact, portable, fast, and energy-efficient devices. One approach to making energy-efficient devices is an in-memory computation that addresses the memory bottleneck issues of the present computing system by utilizing a spintronic device viz. magnetic tunnel junction (MTJ). Further, area and energy can be reduced throug...

In this paper, synchronization of two simple chaotic oscillators with experimental verification is presented. Each chaotic oscillator is the combination of two simple transistors, resistors and capacitors. At the transmitting end, an input signal is masked in the chaotic signal of the master oscillator using a summing circuit and send through the w...

With the advancement of beyond-CMOS devices to keep Moore’s law alive, several emerging devices have found application in a wide range of applications. Spintronic devices offer low power, non-volatility, inherent spatial and temporal randomness, simplicity of integration with a silicon substrate, etc. This makes them a potential candidate for next-...

Spintronics is an important emerging technology for data storage and computation. In this field, magnetic skyrmion-based devices are attractive due to their small size and energy consumption. However, controlling the creation, deletion and motion of skyrmions is challenging. Here we propose a novel energy-efficient skyrmion-based device structure,...

Magnetic skyrmion-based data storage and unconventional computing devices have gained increasing attention due to their topological protection, small size, and low driving current. However, skyrmion creation, deletion, and motion are still being studied. In this study, we propose a skyrmion-based neuromorphic magnetic tunnel junction (MTJ) device w...

We present a magnetic tunnel junction (MTJ) based implementation of the spike time-dependent (STDP) learning for pattern recognition applications. The proposed hybrid scheme utilizes the spin-orbit torque (SOT) driven neuromorphic device-circuit co-design to demonstrate the Hebbian learning algorithm. The circuit implementation involves the (MTJ) d...

The increasing threat of security attacks on hardware security applications has driven research towards exploring beyond CMOS devices as an alternative. Spintronic devices offer advantages like low power, non-volatility, inherent spatial and temporal randomness, simplicity of integration with a silicon substrate, etc., making them a potential candi...

With the advancement of beyond CMOS devices, a new approach to utilize the inherent physics of such emerging structures for various applications is of great interest in recent research. Spintronics-based devices offer key advantages like ease of fabrication with Si-substrate, non-volatile memory, low operational voltage, and non-linear device chara...

The present work discusses the proposal of a spintronic neuromorphic system with spin orbit torque driven domain wall motion-based neuron and synapse. We propose a voltage-controlled magnetic anisotropy domain wall motion based magnetic tunnel junction neuron. We investigate how the electric field at the gate (pinning site), generated by the voltag...

In this work we present the creation, annihilation and dynamics of a topologically protected magnetic structure, a skyrmion, for neuromorphic computing application. We study the effect of Dzyaloshinskii Moriya interaction (DMI) and surface anisotropy on the skyrmion density. The relation between skyrmion annihilation threshold anisotropy Kth and DM...

In this work we present the creation, annihilation and dynamics of a topologically protected magnetic structure, a skyrmion, for neuromorphic computing application. We study the effect of Dzyaloshinskii Moriya interaction (DMI) and surface anisotropy on the skyrmion density. The relation between skyrmion annihilation threshold anisotropy Kth and DM...

The present work discusses the proposal of a spintronic neuromorphic system with spin orbit torque driven domain wall motion-based neuron and synapse. We propose a voltage-controlled magnetic anisotropy domain wall motion based magnetic tunnel junction neuron. We investigate how the electric field at the gate (pinning site), generated by the voltag...

The present work discusses the proposal of a spintronic neuromorphic system with spin orbit torque driven domain wall motion-based neuron and synapse. We propose a voltage-controlled magnetic anisotropy domain wall motion based magnetic tunnel junction neuron. We investigate how the electric field at the gate (pinning site), generated by the voltag...

We report a highly sensitive and miniature in-plane resonant Lorentz-force magnetic micro-sensor operating in air at atmospheric pressure. The concept is based on the detection of the resonance frequency shift of an electrothermally heated initially curved micro-beam experiencing the veering phenomenon (avoided crossing) between its first and third...

We examine a multistate logic computation scheme based on nanomagnets with configurational anisotropy (CA). We present a case study of a structure comprising a thin equilateral triangle—exhibiting sixfold CA—and three surrounding bistable inputs/outputs, where all nanomagnets generally can be interconnected by nanomagnetic chains and adiabatically...

Flow cytometers are important instruments for biological and biomedical analyses. These instruments are large and expensive, and researchers are continuously striving to come up with smaller, cheaper, and more energy-efficient flow cytometers. In this work, we present a highly-sensitive magnetic tunnel junction (MTJ) based flow cytometer. An extern...

Flexible electronics is an emerging field in many applications ranging from in vivo biomedical devices to wearable smart systems. The capability of conforming to curved surfaces opens the door to add electronic components to miniaturized instruments, where size and weight are critical parameters. Given their prevalence on the sensors market, flexib...

In this work, we report the fabrication and characterization of novel four and six terminal current-driven magnetic memory cells. In particular, we experimentally demonstrate the magnetization switching of triangular and square magnets through spin-orbit torque by in-plane currents in a Pt/NiFe (Py) heterostructure. The spin torques, generated by a...

The write endurance and the 1/f noise of electrical origin were characterized in CoFeB/MgO/CoFeB magnetic tunnel junctions (MTJ) for spin transfer torque or thermally assisted magnetic random access memories. A statistical study carried out on a set of 60 nominally identical patterned junctions of 200 nm diameter revealed a correlation trend betwee...

The thesis objective is to study the Magnetic Tunnel Junction reliability and cyclability to more understand the barrier breakdown mechanisms. An investigation of barrier endurance till electrical breakdown in MgO-based magnetic tunnel junctions (MTJs) is presented. Samples were tested under pulsed electrical stress. By studying the effect of delay...

An investigation of barrier breakdown in MgO-based magnetic tunnel junctions (MTJs) submitted to pulsed electrical stress is presented. By studying the effect of delay between successive pulses, we observed that a very pronounced optimum in endurance of MTJs is obtained for an intermediate value of the delay between pulses corresponding to the char...

An investigation of barrier endurance till electrical breakdown in MgO-based magnetic tunnel junctions (MTJs) is presented. Samples were tested under pulsed electrical stress. By studying the effect of delay between successive pulses, an optimum endurance of MTJs is observed for an intermediate value of delay between pulses corresponding to an opti...

A thorough investigation of barrier breakdown in MgO based Magnetic Tunnel Junctions is presented. Our samples were tested under pulsed electrical stress. By studying the effect of delay between two pulses, we observe that an optimum endurance of MTJs is obtained for an intermediate value of delay between pulses which allows a partial discharge of...

Endurance of MgO-based magnetic tunnel junctions has been studied using a time-dependent dielectric breakdown method. Series of successive electrical pulses were applied until electrical breakdown of the tunnel barrier. We show that two electrical breakdown regimes exist depending on the time interval Deltat between pulses compared to a characteris...

The charge and spin diffusion equations taking into account spin-flip and spin-transfer torque were numerically solved using a finite element method in complex non-collinear geometry with strongly inhomogeneous current flow. As an illustration, spin-dependent transport through a non-magnetic nanoconstriction separating two magnetic layers was inves...

The charge and spin diffusion equations taking into account spin-flip and spin-transfer torque were numerically solved using a finite element method in complex non-collinear geometry. This approach was used to study the spin-dependent transport in giant magnetoresistance metallic pillars sandwiched between extended electrodes as in magnetoresistive...

Charge- and spin-diffusion equations, taking into account spin-diffusion and spin-transfer torque, were numerically solved using a finite element method in complex noncollinear geometry. As an illustration, this approach was used to study the spin-dependent transport in a two-dimensional model giant magnetoresistance metallic pillar sandwiched betw...

The charge and spin diffusion equations taking into account spin-flip and spin-transfer torque were numerically solved using a finite element method in complex non-collinear geometry. As an illustration, spin-dependent transport through a non-magnetic nanoconstriction separating two magnetic layers was investigated. Unexpected results such as vorti...