A5076055468- Magnetic properties of thin films
- Magnetic Properties and Applications
- Physics of Superconductivity and Magnetism
- Magnetic and transport properties of perovskites and related materials
- Theoretical and Computational Physics
- Quantum and electron transport phenomena
- Advanced Memory and Neural Computing
- Multiferroics and related materials
- ZnO doping and properties
- Ferroelectric and Negative Capacitance Devices
- Characterization and Applications of Magnetic Nanoparticles
- Magnetic Properties of Alloys
- Magnetic Field Sensors Techniques
- Magneto-Optical Properties and Applications
- Semiconductor materials and devices
- 2D Materials and Applications
- Phase-change materials and chalcogenides
- Graphene research and applications
- Advanced Data Storage Technologies
- Topological Materials and Phenomena
- Molecular Junctions and Nanostructures
- Non-Destructive Testing Techniques
- Advanced Electron Microscopy Techniques and Applications
- Diamond and Carbon-based Materials Research
- Anodic Oxide Films and Nanostructures
Centre National de la Recherche Scientifique
2015-2025
CEA Grenoble
2015-2025
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2015-2025
Université Grenoble Alpes
2015-2025
Spintronique et Technologie des Composants
2016-2025
Institut polytechnique de Grenoble
2011-2024
Lomonosov Moscow State University
2019
Istituto Nazionale di Ricerca Metrologica
2019
Polytechnic University of Turin
2019
Institut Nanosciences et Cryogénie
2011-2018
Spin-orbit torques induced by spin Hall and interfacial effects in heavy metal/ferromagnetic bilayers allow for a switching geometry based on in-plane current injection. Using this geometry, we demonstrate deterministic magnetization reversal pulses ranging from 180~ps to ms Pt/Co/AlOx dots with lateral dimensions of 90~nm. We characterize the probability critical $I_c$ as function pulse length, amplitude, external field. Our data evidence two distinct regimes: short-time intrinsic regime,...
We report on the current-induced magnetization switching of a three-terminal perpendicular magnetic tunnel junction by spin-orbit torque and its read-out using tunnelling magnetoresistance (TMR) effect. The device is composed Ta/FeCoB/MgO/FeCoB stack top Ta current line. bottom FeCoB layer can be switched reproducibly injection pulses with density 5 × 1011 A/m2 in presence an in-plane bias field, leading to full-scale change TMR signal. Our work demonstrates proof concept memory cell.
Electric control of magnetism is a prerequisite for efficient and low power spintronic devices. More specifically, in heavy metal/ ferromagnet/ insulator heterostructures, voltage gating has been shown to locally dynamically tune magnetic properties like interface anisotropy saturation magnetization. However, its effect on interfacial Dzyaloshinskii-Moriya Interaction (DMI), which crucial the stability skyrmions, challenging achieve not reported yet ultrathin films. Here, we demonstrate 130%...
We show that the Dzyaloshinskii-Moriya interaction (DMI) can lead to a tilting of domain wall (DW) surface in perpendicularly magnetized magnetic nanotracks when DW dynamics are driven by an easy axis field or spin polarized current. The affects for large DMI, and relaxation time be very as it scales with square track width. results well explained extended collective coordinate model where DMI included. propose simple way estimate multilayers measuring dependence tilt angle on transverse...
We present a comprehensive study of the current-induced spin-orbit torques in perpendicularly magnetized Ta/CoFeB/MgO layers. The samples were annealed steps up to 300 degrees C and characterized using x-ray absorption spectroscopy, transmission electron microscopy, resistivity, Hall effect measurements. By performing adiabatic harmonic voltage measurements, we show that transverse (field-like) longitudinal (antidamping-like) are composed constant magnetization-dependent contributions, both...
Using first-principles calculations, we demonstrate several approaches to control Dzyaloshinskii-Moriya Interaction (DMI) in ultrathin films with perpendicular magnetic anisotropy. First, find that DMI is significantly enhanced when the ferromagnetic (FM) layer sandwiched between nonmagnetic (NM) layers inducing additive NM1/FM/NM2 structures. For instance, two NM are chosen induce of opposite chirality Co, e.g. NM1 representing Au, Ir, Al or Pb, and NM2 being Pt, resulting NM1/Co/Pt...
We demonstrate ultra-fast (down to 400 ps) bipolar magnetization switching of a three-terminal perpendicular Ta/FeCoB/MgO/FeCoB magnetic tunnel junction. The critical current density rises significantly as the pulse shortens below 10 ns, which translates into minimum in write energy nanosecond range. Our results show that spin-orbit torque-MRAM allows for fast and low-power operations, makes it promising non-volatile cache memory applications.
Magnetic skyrmions are deemed to be the forerunners of novel spintronic memory and logic devices. While their observation current-driven motion at room temperature have been demonstrated, certain issues regarding nucleation, stability, pinning, skyrmion Hall effect still need overcome realize functional Here, we demonstrate that focused He+-ion-irradiation can used create guide in racetracks. We show reduction perpendicular magnetic anisotropy Dzyaloshinskii–Moriya interaction track defined...
Magnetic skyrmions are topological magnetic textures that hold great promise as nanoscale bits of information in memory and logic devices. Although room-temperature ferromagnetic their current-induced manipulation have been demonstrated, velocity has limited to about 100 meters per second. In addition, dynamics perturbed by the skyrmion Hall effect, a motion transverse current direction caused charge. Here, we show compensated synthetic antiferromagnets can be moved along at velocities up...
The nucleation of reversed magnetic domains in Pt/Co/AlO$_{x}$ microstructures with perpendicular anisotropy was studied experimentally the presence an in-plane field. For large enough field, observed preferentially at edge sample normal to this position which takes place depend a chiral way on initial magnetization and applied field directions. An explanation these results is proposed, based existence sizable Dzyaloshinskii-Moriya interaction sample. Another consequence that energy domain...
This paper deals with a new MRAM technology whose writing scheme relies on the Spin Orbit Torque (SOT). Compared to Transfer (STT) MRAM, it offers very fast switching, quasi-infinite endurance and improves reliability by solving issue of "read disturb", thanks separate reading paths. These properties allow introducing SOT at all-levels memory hierarchy systems adressing applications which could not be easily implemented STT-MRAM. We present this emerging full design framework, allowing...
The current-driven motion of magnetic skyrmions is an essential functionality for next-generation memory and logic devices. This paper provides a complete, detailed experimental study model system composed ultrathin Pt/Co/MgO film, in which 100-nm move at high speeds 100 m/s exhibit velocity-dependent skyrmion Hall effect. Detailed characterization the film properties using experiment, analytical modeling, micromagnetic simulation reveals that this behavior can be fully accounted by pinning...
Magnetic skyrmions are topologically nontrivial spin textures which hold great promise as stable information carriers in spintronic devices at the nanoscale. One of major challenges for developing novel skyrmion-based memory and logic is fast controlled creation magnetic ambient conditions. Here we demonstrate single ultrafast (35-fs) laser pulse-induced generation skyrmion bubbles bubble lattices from a ferromagnetic state sputtered ultrathin films room temperature. The density increases...
Magnetic skyrmions are topological spin textures that hold great promise as nanoscale information carriers in non-volatile memory and logic devices. While room-temperature magnetic their current-induced manipulation were recently demonstrated, the stray field resulting from finite magnetization well charge limit minimum size reliable motion tracks. Antiferromagnetic (AF) allow these limitations to be lifted owing vanishing net zero charge, promising room-temperature, ultrasmall skyrmions,...
In recent years, two-dimensional van der Waals materials have emerged as an important platform for the observation of long-range ferromagnetic order in atomically thin layers. Although heterostructures such can be conceived to harness and couple a wide range magneto-optical magneto-electrical properties, technologically relevant applications require Curie temperatures at or above room-temperature ability grow films over large areas. Here we demonstrate large-area growth single-crystal...
Van der Waals heterostructures have promised the realisation of artificial materials with multiple physical phenomena such as giant optical nonlinearities, spin-to-charge interconversion in spintronics and topological carrier protection, a single layered device through an infinitely diverse set quantum materials. However, most efforts only focused on exfoliated material that inherently limits both dimensions scalability for applications. Here, we show epitaxial growth large area insulators...
Current induced domain wall (DW) depinning of a narrow DW in out-of-plane magnetized (Pt/Co)_{3}/Pt multilayer elements is studied by magnetotransport. We find that for conventional measurements Joule heating effects conceal the real spin torque efficiency and so we use measurement scheme at constant sample temperature to unambiguously extract contribution. From variation magnetic field with current pulse amplitude directly deduce large nonadiabaticity factor this material its consistent...
We demonstrate magnetization switching of a perpendicularly magnetized MgO/Co/Pt trilayer by application an in-plane current and constant magnetic field small amplitude. Switching occurs due to effective torque generated spin-orbit coupling intrinsic the structure. investigate dependence critical on pulse width, showing that reversal in dc limit is assisted thermal fluctuations.
We investigate spin-orbit torque (SOT)-induced switching in rare-earth-transition metal ferrimagnetic alloys using W/CoTb bilayers. The current is found to vary continuously with the alloy concentration, and no reduction observed at magnetic compensation point despite a very large SOT efficiency. A model based on coupled Landau-Lifschitz-Gilbert (LLG) equations shows that density scales effective perpendicular anisotropy which does not exhibit strong compensation, explaining behavior of...