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Reference : UMR5221-ISAPHI-004
Workplace : MONTPELLIER
Date of publication : Monday, December 02, 2019
Type of Contract : FTC Scientist
Contract Period : 12 months
Expected date of employment : 1 January 2020
Proportion of work : Full time
Remuneration : between 1950 and 2350 € net monthly salary
Desired level of education : PhD
Experience required : 1 to 4 years
Within the framework of the DARPA project on “Topological Excitations in Electronics “, a one-year post-doctoral position is immediately available in the Laboratoire Charles Coulomb located in Montpellier, France.
Magnetic skyrmions are topological defects with a whirling spin texture, which are currently attracting tremendous interest for spintronic applications owing to their small sizes, high stability and ability to be moved with currents. After years of intense research, ferromagnetic skyrmions can now be stabilized at room temperature in technologically-relevant materials based on magnetic multilayer stacks lacking inversion symmetry. Despite many impressive results recently reported in the literature, ferromagnetic skyrmions suffer from at least three limitations in view of applications. First, strong dipolar interactions inherent to ferromagnetic materials prevent the stabilization of ferromagnetic skyrmions with very small size. Second, current-induced skyrmion motion along a track is disturbed by a transverse deflection resulting from the Magnus force, a phenomenon coined as skyrmion-Hall effect, which is a direct consequence of topology. Third, large current densities are still required to move efficiently ferromagnetic skyrmion and their velocity hardly exceeds a few tens of meters per second.
In principle, all these limitations can be circumvented by working with skyrmions in antiferromagnetic materials (AF). The goal of this project is (i) to identify antiferromagnetic skyrmions with diameters below 10 nm and (ii) to investigate their motion under current pulses. Two type of magnetic systems will be explored: BiFeO3, a prototypical multiferroic material in which antiferromagnetism coexists with ferroelectricity, and NiO, an insulating material with a G-type AF order. The post-doc work will be first focused on magnetic simulations aiming at identifying (i) how to stabilize skyrmions in these materials and (ii) how to manipulate such spin textures with current pulses. Magnetic imaging will then be conducted with a scanning-NV magnetometer operating under ambient conditions.
- Theoretical developments
- Experiments by scanning magnetic microscopy
The candidate should hold a PhD degree. Previous research experience in condensed matter physics with a strong expertise on numerical simulations using dynamical atomistic magnetic simulations is required. Our team is also strongly committed to workplace diversity, sustained not only by the open and multicultural environment but also thanks to flexible working arrangements enabling work-life balance for both women and men.
This project will be carried in a scientific environment providing
- world‐class research facilities, with two NV centers-based quantum sensing benches operating at room temperature with state-of-the-art performances.
- partnership with international well-established collaborations
- participation to international conferences and outreach activities
Constraints and risks
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