Article
Engineering, Electrical & Electronic
Hugo Nicolas, Ricardo C. Sousa, Ariam Mora-Hernandez, Ioan-Lucian Prejbeanu, Luc Hebrard, Jean-Baptiste Kammerer, Joris Pascal
Summary: This article presents a new type of magnetic sensor using a perpendicular spin transfer torque magnetic tunnel junction (MTJ). The sensor has a cylindrical shape with a diameter of 50 nm, making it one of the smallest magnetic sensors reported. The article discusses the principle of operation, signal processing electronics, experimental results, and comparisons to existing magnetic sensors. The sensor demonstrates high sensitivity and dynamic range, and its compatibility with standard microelectronics components allows for integration with conditioning electronics.
IEEE SENSORS JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Hugo Nicolas, Ricardo C. Sousa, Ariam Mora-Hernandez, Ioan-Lucian Prejbeanu, Luc Hebrard, Jean-Baptiste Kammerer, Joris Pascal
Summary: This article presents a new type of magnetic sensor using a perpendicular spin transfer torque magnetic tunnel junction (MTJ). The sensor has a cylindrical shape with a diameter of 50 nm, making it one of the smallest ever reported. The article describes the principle of operation, signal processing electronics, and compares its performance with commercially available sensors. The developed sensor has a sensitivity of 1.28 V/T, a dynamic range of 80 mT, and a noise level of 21.8 μT/√Hz. The sensor and its electronics are compatible with existing fabrication processes, allowing for mass production in various markets.
IEEE SENSORS JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Jyotirmoy Chatterjee, Paulo Coelho, Antoine Chavent, Ricardo C. Sousa, Stephane Auffret, Claire Baraduc, Ioan-Lucian Prejbeanu, Bernard Dieny
Summary: In this study, a novel class of hard and out-of-plane magnetized seedless multilayers consisting of [Co/insertion layer/Pt](n) was investigated for potential applications as top reference layers in magnetic tunnel junctions (MTJ). Among various nonferrous insertion layers tested, Ta was found to exhibit the highest perpendicular magnetic anisotropy. By using Ta-inserted SL-MLs, a back-end-of-line (BEOL) compatible top reference layer with more than double the effective perpendicular anisotropy of a conventional top reference layer was achieved. Three types of spintronic memory stacks were developed using this top reference layer, each with unique features and capabilities, such as the ability to withstand high-temperature annealing, faster readout and low-voltage writing, and combining different writing techniques for increased efficiency.
ACS APPLIED ELECTRONIC MATERIALS
(2021)
Article
Engineering, Electrical & Electronic
T. Patrick Xiao, Christopher H. Bennett, Frederick B. Mancoff, Jack E. Manuel, David R. Hughart, Robin B. Jacobs-Gedrim, Edward S. Bielejec, Gyorgy Vizkelethy, Jijun Sun, Sanjeev Aggarwal, Reza Arghavani, Matthew J. Marinella
Summary: The study evaluated the resilience of CoFeB/MgO/CoFeB magnetic tunnel junctions (MTJs) with perpendicular magnetic anisotropy (PMA) to displacement damage induced by heavy-ion irradiation. It found that damage to the MgO interfaces led to a decrease in magnetoresistance and PMA, elucidating the thresholds for significant irreversible changes in the characteristics of STT-MRAM devices.
IEEE TRANSACTIONS ON NUCLEAR SCIENCE
(2021)
Article
Computer Science, Information Systems
Sreevatsan Rangaprasad, Vinod Kumar Joshi
Summary: Spintronics offers novel computational paradigms without leakage effects and volatility issues of traditional CMOS systems. This paper proposes a fully non-volatile reconfigurable magnetic arithmetic logic unit (NVRMALU) based on majority logic, which shows remarkable power reduction compared to contemporary designs and is superior in power reduction compared to double pass transistor clocked CMOS (DPTLCMOS) ALU. This design demonstrates the feasibility of non-volatile and dynamic reconfigurable traits and has potential for multi-bit applications.
Article
Engineering, Electrical & Electronic
Vikas Nehra, Sanjay Prajapati, T. Nandha Kumar, Brajesh Kumar Kaushik
Summary: This study utilizes a differential spin Hall (DSH)-MRAM cell for logic and circuit applications, storing a pair of complementary bits with low energy consumption and reduced area. Compared to CMOS-based multipliers, the proposed hybrid CMOS/MTJ multipliers show significant improvements in power consumption and power-delay product characteristics.
SEMICONDUCTOR SCIENCE AND TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Sreevatsan Rangaprasad, Vinod Kumar Joshi, Brajesh Kumar Kaushik
Summary: This paper presents a fully Non -Volatile Reconfigurable Magnetic Decoder using Magnetic Tunnel Junction (MTJ) as the spin device, following the Logic-In-Memory (LIM) architecture. The proposed design aims to tackle issues in CMOS and outperforms competitors in terms of low power, less delay, and dynamic reconfigurability.
MICROELECTRONICS JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Santiago S. Perez, Alessandro Bedoya, Luis Miguel Procel, Ramiro Taco
Summary: This study utilizes double-barrier magnetic tunnel junction (DMTJ) technology to define STT-MRAM at the circuit level. The results indicate that the tunnel-FET based solution is the most energy-efficient alternative with lower leakage current.
INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS
(2023)
Article
Engineering, Electrical & Electronic
Manoj Kumar Yadav, Santosh Kumar Gupta
Summary: This study presents a first principle analysis of Fe/MgO/Fe magnetic tunnel junctions (MTJ) with gate voltage control over the insulated barrier region. The results show that the different work functions of the gate and barrier materials lead to the transfer of density of states (DOS) in the forbidden energy gap of MgO due to the Schottky effect. The high spin injection efficiency and tunnel magneto resistance (TMR) ratios observed in this study indicate the potential of MTJs as three-terminal devices for magnetic random access memory (MRAM) applications.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Computer Science, Information Systems
Gulafshan Gulafshan, Selma Amara, Rajat Kumar, Danial Khan, Hossein Fariborzi, Yehia Massoud
Summary: Today's technology requires devices that are compact, portable, fast, and energy-efficient. This paper presents a circuit design based on voltage-controlled magnetic anisotropy magnetoresistive random access memory (VCMA-MRAM), which utilizes logic-in-memory computing paradigm and approximate computation to address the memory bottleneck issues in the present computing system. Simulation results demonstrate that the proposed circuit's approximate adder consumes about 300% less energy and is 2.3 times faster than its exact counterpart.
Article
Engineering, Electrical & Electronic
Shivam Verma, Ravneet Paul, Mayank Shukla
Summary: This article introduces a novel non-volatile latch for logic-in-memory computing. The proposed latch has a simple design, high stability, and compatibility with CMOS logic styles. It also has fewer transistors and lower power consumption. Additionally, the write circuit is modified to reduce power consumption and area requirement.
IEEE TRANSACTIONS ON MAGNETICS
(2022)
Article
Computer Science, Hardware & Architecture
Lizhou Wu, Siddharth Rao, Mottaqiallah Taouil, Erik Jan Marinissen, Gouri Sankar Kar, Said Hamdioui
Summary: The article introduces a new magnetic-field-aware compact model for magnetic/electrical co-simulation of spin-transfer torque magnetic random access memories (STT-MRAMs). The model is calibrated using magnetic measurement data of MTJ devices and demonstrated its superiority for device/circuit co-design of STT-MRAM.
IEEE TRANSACTIONS ON COMPUTER-AIDED DESIGN OF INTEGRATED CIRCUITS AND SYSTEMS
(2022)
Article
Engineering, Electrical & Electronic
Hamdam Ghanatian, Hooman Farkhani, Yasser Rezaeiyan, Tim Bohnert, Ricardo Ferreira, Farshad Moradi
Summary: This article presents a 3-bit Flash spin-orbit torque analog-to-digital converter (SOT-ADC) that utilizes the spin Hall effect assisted by spin-transfer torque to switch a perpendicular-anisotropy magnetic tunnel junction. By utilizing heavy metal and fixed currents for sensing, the ADC eliminates the need for power-hungry comparators and reduces mismatch issues and chip area.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Computer Science, Information Systems
Esteban Garzon, Marco Lanuzza, Ramiro Taco, Sebastiano Strangio
Summary: This study compares FinFET- and TFET-based STT-MRAM bitcells operating at ultralow voltages, with TFET solutions showing greater resilience to process variations, ability to operate at ultralow voltages (<0.5V), energy savings of over 50%, and faster write switching by 60%.
Article
Engineering, Electrical & Electronic
Jagadish Rajpoot, Shivam Verma
Summary: This paper proposes a non-volatile latch based on spin transfer torque (STT) based magnetic tunnel junction (MTJ) device, which has an auto-write-terminate (AWT) feature. The proposed latch has a simple structure, better stability, and higher speed, and is easy to integrate with CMOS logic styles. It also saves power and transistors by not requiring an additional write driver circuit. The AWT circuitry continuously monitors the write operation, preventing redundant MTJ writing and saving write energy.
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS
(2023)
Article
Engineering, Electrical & Electronic
Axel Laborieux, Marc Bocquet, Tifenn Hirtzlin, Jacques-Olivier Klein, Etienne Nowak, Elisa Vianello, Jean-Michel Portal, Damien Querlioz
Summary: The paper focuses on the implementation of ternary neural networks and proposes a two-transistor/two-resistor memory architecture for achieving high energy efficiency at low supply voltage, while studying the bit error rate. Experimental results demonstrate that ternary neural networks can significantly improve neural network performance and exhibit immunity to bit errors.
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS
(2021)
Article
Engineering, Electrical & Electronic
Guanda Wang, Yue Zhang, Zhizhong Zhang, Zhenyi Zheng, Kun Zhang, Jinkai Wang, Jacques-Olivier Klein, Dafine Ravelosona, Weisheng Zhao
Summary: In this work, a highly efficient XNOR logic gate leveraging the thermal effect on FiM DW motions is proposed, with its functionality and advantageous performance confirmed by micromagnetic simulations. Furthermore, majority logic and full adder functions can be reconfigured based on the proposed scheme. Lastly, a fully FiM DW based binary neural network (BNN) is built, providing low energy consumption, short delay and excellent accuracy.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Romeo Juge, Kaushik Bairagi, Kumari Gaurav Rana, Jan Vogel, Mamour Sall, Dominique Mailly, Van Tuong Pham, Qiang Zhang, Naveen Sisodia, Michael Foerster, Lucia Aballe, Mohamed Belmeguenai, Yves Roussigne, Stephane Auffret, Liliana D. Buda-Prejbeanu, Gilles Gaudin, Dafine Ravelosona, Olivier Boulle
Summary: Magnetic skyrmions can be successfully created and guided in racetrack devices using focused He+-ion-irradiation, leading to stable and isolated skyrmions. By tuning the magnetic properties, the maximum skyrmion velocity can be enhanced, suppressing the skyrmion Hall effect and opening up new possibilities for practical applications.
Article
Physics, Applied
R. Pachat, D. Ourdani, J. W. van der Jagt, M-A Syskaki, A. Di Pietro, Y. Roussigne, S. Ono, M. S. Gabor, M. Cherif, G. Durin, J. Langer, M. Belmeguenai, D. Ravelosona, L. Herrera Diez
Summary: The study reveals the existence of different magnetoionic regimes in Ta/(Co,Fe)B/HfO2 stacks, where a gate voltage drives the transition from underoxidized state to perpendicular anisotropy state. The transition speeds and reversibility between these regimes show significant differences.
PHYSICAL REVIEW APPLIED
(2021)
Article
Engineering, Electrical & Electronic
Atreya Majumdar, Marc Bocquet, Tifenn Hirtzlin, Axel Laborieux, Jacques-Olivier Klein, Etienne Nowak, Elisa Vianello, Jean-Michel Portal, Damien Querlioz
Summary: This study presents a model of weak RESET process in hafnium oxide RRAM for deep learning and validates its effectiveness through experiments with hybrid CMOS/RRAM technology. The model is used to train binarized neural networks for image recognition tasks, showing that device-to-device variability is the most detrimental imperfection affecting the training process.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Materials Science, Multidisciplinary
Christopher J. Jensen, Alberto Quintana, Mamour Sall, Liza Herrera Diez, Junwei Zhang, Xixiang Zhang, Dafine Ravelosona, Kai Liu
Summary: In this study, the effects of helium ion irradiation and oxygen implantation on magneto-ionically induced exchange bias effect in Gd/Ni0.33Co0.67O heterostructures were investigated. Results showed that oxygen migration induced by ion migration can enhance the exchange bias effect, while higher ion fluence can suppress it. In addition, lattice changes caused by oxygen implantation altered the exchange bias effect.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2021)
Article
Multidisciplinary Sciences
Xing Chen, Flavio Abreu Araujo, Mathieu Riou, Jacob Torrejon, Dafine Ravelosona, Wang Kang, Weisheng Zhao, Julie Grollier, Damien Querlioz
Summary: This article introduces a dynamical neural network trained on a minimal amount of data that can predict the behavior of spintronic devices with high accuracy and efficiency. Two experiments are presented to demonstrate the feasibility of the approach.
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
A. Sud, S. Tacchi, D. Sagkovits, C. Barton, M. Sall, L. H. Diez, E. Stylianidis, N. Smith, L. Wright, S. Zhang, X. Zhang, D. Ravelosona, G. Carlotti, H. Kurebayashi, O. Kazakova, M. Cubukcu
Summary: The study demonstrates that helium ion irradiation significantly affects the magnetic properties of multilayers, leading to interface modification. This external degree of freedom holds promising prospects for further improving the control of magnetic skyrmions in multilayers.
SCIENTIFIC REPORTS
(2021)
Review
Physics, Multidisciplinary
Durgesh Kumar, Tianli Jin, Rachid Sbiaa, Mathias Klaui, Subhankar Bedanta, Shunsuke Fukami, Dafine Ravelosona, See-Hun Yang, Xiaoxi Liu, S. N. Piramanayagam
Summary: Digital data generated by corporate and individual users is growing due to the use of digital applications. While flash memory devices are replacing HDDs in certain applications, HDDs still dominate the storage of digital data in cloud and servers. Domain wall memory (DWM) is a potential alternative to HDDs, offering lower power consumption and higher storage capacity. However, there are challenges to be addressed before DWM can become commercially viable.
PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Rohit Pachat, Djoudi Ourdani, Maria-Andromachi Syskaki, Alessio Lamperti, Subhajit Roy, Song Chen, Adriano Di Pietro, Ludovic Largeau, Romeo Juge, Maryam Massouras, Cristina Balan, Johannes Wilhelmus van der Jagt, Guillaume Agnus, Yves Roussigne, Mihai Gabor, Salim Mourad Cherif, Gianfranco Durin, Shimpei Ono, Jurgen Langer, Damien Querlioz, Dafine Ravelosona, Mohamed Belmeguenai, Liza Herrera Diez
Summary: The magneto-ionic modulation of the Dzyaloshinskii-Moriya interaction (DMI) and the perpendicular magnetic anisotropy (PMA) in W/CoFeB/HfO2 stacks is investigated by annealing at different temperatures and for varying annealing times. It is found that a large modulation of PMA and DMI is observed in the systems annealed at 390 and 350 degrees C, while no response to voltage is observed in the as-grown samples. The magnetic properties, including domain wall velocity, improve significantly with increasing annealing temperature and time, but the magneto-ionic reversibility is compromised.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Physics, Applied
Pingzhi Li, Johannes W. van der Jagt, Maarten Beens, Julian Hintermayr, Marcel A. Verheijen, Rene Bruikman, Beatriz Barcones, Romeo Juge, Reinoud Lavrijsen, Dafine Ravelosona, Bert Koopmans
Summary: In this paper, the enhancement of all-optical switching (AOS) in Co/Gd synthetic ferrimagnets by He ion irradiation is explored. The intermixing of magnetic layers caused by He ion irradiation significantly enhances AOS, and the threshold fluence of AOS can be reduced by almost 30%. This study reveals the potential of He ion irradiation for industrially compatible local AOS engineering.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Applied
Cristina Balan, Johannes W. van der Jagt, Jose Pena Garcia, Jan Vogel, Laurent Ranno, Marlio Bonfim, Dafine Ravelosona, Stefania Pizzini, Vincent Jeudy
Summary: The effect of He+ irradiation on the dynamics of chiral domain walls in Pt/Co/AlOx trilayers in the creep regime was studied. Irradiation resulted in a strong decrease in the depinning field and a non-monotonous change of the effective pinning barriers. The variations of domain wall dynamics were mainly due to the strong decrease in the effective anisotropy constant, which increased the domain wall width. However, the strength of the domain wall-disorder interaction was weakly impacted by the irradiation, suggesting that the length-scales of the disorder fluctuation remained smaller than the domain wall width.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Applied
G. Masciocchi, J. w. Van Der Jagt, M. -A. Syskaki, J. Langer, G. Jakob, J. Mccord, B. Borie, A. Kehlberger, D. Ravelosona, M. Klaeui
Summary: In this study, it was found that the use of He+ irradiation significantly improves the magnetic softness and magnetostriction of a 30-nm permalloy film. The irradiation treatment results in a reduction in anisotropy and coercivity, as well as a significant decrease in magnetostriction. These improvements are attributed to isotropic crystallite growth and intermixing at the magnetic layer interfaces.
PHYSICAL REVIEW APPLIED
(2023)
Proceedings Paper
Automation & Control Systems
Bogdan Penkovsky, Marc Bocquet, Tifenn Hirtzlin, Jacques-Olivier Klein, Etienne Nowak, Elisa Vianello, Jean-Michel Portal, Damien Querlioz
PROCEEDINGS OF THE 2020 DESIGN, AUTOMATION & TEST IN EUROPE CONFERENCE & EXHIBITION (DATE 2020)
(2020)
