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General information

Workplace: Institut Jean Lamour, University of Lorraine, Nancy, France + 12 months secondment at the Center for Quantum Phenomena (New York University )
Type of contract: PhD contract funded by LUE (
https://www.univ-lorraine.fr/lue/ )
Contract period: 36 months
Expected date of employment: October 2022
Proportion of work: Full time
Remuneration:  –
Desired level of education:
Master’s degree in physics, material science or nanophysics.

Experience required: –

 

Subject description

Magnetic skyrmions are topological spin textures. Since the experimental discovery of the Dzyaloshinskii–Moriya interaction (DMI) at the interfaces of thin film structure, they have been a center of interest for the nanomagnetism community. The interfacial DMI is a antisymmetric exchange interaction that establishes a preferred chirality for spin textures, making it a key ingredient for the formation of skyrmions in two-dimensional magnetic systems and nanoscale thin-film multilayers. Magnetic skyrmions are anticipated to be used as bits to store information in future memory and logic devices. To allow skyrmions-based nanodevices with dense integration and low energy cost, isolated skyrmions nucleated at room temperature which can be displaced and annihilated using current pulses and can be detected electrically are needed. Moreover, smaller skyrmion sizes (from the 100 nm to the 10 nm range) should be obtained together with reliable current-induced motion (faster velocities combined with further reduced depinning currents).

 

A problem with skyrmions in a ferromagnet layer is that because of strong magnetic dipolar interactions it is impossible to obtain ultra-small skyrmions and it is difficult to stabilize them. The dipolar interaction can also reduce the speed of those skyrmions. Furthermore, a consequence of the topology of ferromagnetic skyrmions on their dynamics is their deflection with respect to the direction of any driving force, known as the skyrmion Hall effect.

 

The goal of this project is to develop the study of skyrmions dynamics in perpendicular magnetization coupled anti-ferromagnetic (Synthetic Anti-Ferromagnetic or ferrimagnetic – SAF) multilayer structures. In antiferromagnets (ferrimagnet), two coupled equivalent magnetic subsystems align antiparallel to each other with no net (weak net) magnetic moment, which reduce the dipolar fields. These types of multilayers may enable small, easy to nucleate and fast skyrmions. Moreover, the skyrmion Hall effect is compensated in antiferromagnets and thus the cancellation of the transverse motion should allow efficient skyrmion motion along the driving force direction, which is crucial for most skyrmion-based applications. It has been shown using rare-earth transition metal ferrimagnets that skyrmions can be formed even in thick films [1] and that it is possible to tune Dzyaloshinskii-Moriya interactions in GdCo ferrimagnetic alloys [2,3]. Recently, we have shown a large self-production of spin current in rear-earth transition metal ferrimagnets thanks to the strong spin-orbit coupling in 5d bands of the rear-earth [4] that could be used to manipulate skyrmions. Moreover, we have shown skyrmions nucleation by fs laser pulses [5].

 

In this context the objectives of this project are: i) To grow synthetic antiferromagnets or synthetic ferrimagnets which allows the creation of skyrmions and to control and reduce the magnetic dipolar interaction, ii) To study the properties of skyrmions in these heterostructures, and iii) To study the dynamic of the skyrmions either by applying electrical current or fs laser pulses.

 

The selected PhD student will optimize nanostructure growth as well as optimize the system and approach to nucleate skyrmions and, depending on progress, to perform the manipulation of such skyrmions by electrical and/or optical means. She/he will work on an experimental setup for electronic transport characterization at the state of the art [2,3,4]. Moreover, she/he use and develop new experimental setups, contribute to their improvement, participate to the interpretation of the results obtained and propose new experiments. This thesis is funded by Lorraine Université d’Excellence (LUE) program. The PhD will also perform about 12 months internship at Prof. Kent’s group in New York University with additional funding provided by sources from NYU for New York City accommodations. Prof. Kent is Director of Center for Quantum Phenomena (CQP) at NYU. He is also Dr. Honoris Causa by Lorraine University.

 

References

[1] Woo et al., Nat. Comm. 9, 959 (2018)

[2] Quessab, Kent, et al., Sci. Rep. 10, 1 (2020)

[3] Quessab, Kent, et al. Adv. Science 8, 210048 (2021)

[4] Cespedes-Berrocal, et al., Adv. Mater. 33, 2007047 (2021)

[5] Je et al., Nano Lett. 18, 7362 (2018)

Keywords: spin current, ferrimagnet, antiferromagnet, spin-orbit torque, skyrmions.

 

Work context

The PhD student will work within the Spintronic and Nanomagnetism research group  https://spin.ijl.cnrs.fr  under the supervision of Dr. J. Carlos Rojas-Sánchez and within the Center for Quantum Phenomena under the supervision of Prof. Andy Kent from NYU

https://as.nyu.edu/content/nyu-as/as/faculty/andrew-d-kent.html .

 

Skills

Knowledge of Solid State Physics, including magnetism and electronic transport properties is essential.

Knowledge of English (oral and written) is important and knowledge of French would be an advantage.

As an enthusiastic researcher you like team work, and have a flexible approach to collaborating between different laboratories. Taste in both experimental and theoretical work is of added interest.

 

Constraints and risks

No major risk.

 

About Institut Jean Lamour

The Institute Jean Lamour (IJL) is a joint research unit (UMR 7198) of CNRS and Université de Lorraine.

Focused on materials and processes, science and engineering, it covers: materials, metallurgy, plasmas, surfaces, nanomaterials and electronics. It regroups 183 researchers/lecturers, 91 engineers/technicians/administrative staff, 150 doctoral students and 25 post-doctoral fellows. Partnerships exist with 150 companies and our research groups collaborate with more than 30 countries throughout the world. Its exceptional instrumental platforms are spread over 4 sites; the main one is located on Artem campus in Nancy.

 

The project will be carried out within the SPIN team whose subjects range from the development of innovative materials for implementation in spin electronics devices, to the development of magnetic sensors and the fundamental study of physical phenomena related to magnetism.

 

Application

Application should be performed trough https://www.adum.fr/ by May 31st. 3 candidates will be pre-selected for an interview in early June.

 

Also by email, but please use the following subject:

“NAME application for LUE PhD 2022” where NAME stands for your last name.

Applicants are invited to send a CV and cover letter together with diploma copies to:

 

·         J. Carlos Rojas-Sánchez (CNRS Researcher) : juan-carlos.rojas-sanchez@univ-lorraine.fr

·          Andrew Kent (NYU CQP Director) andy.kent@nyu.edu

General information

 

Workplace: Institut Jean Lamour, University of Lorraine, Nancy, France + 12 months secondment at the Cavendish Laboratory, Cambridge University, UK
Type of contract: PhD contract funded by LUE (
https://www.univ-lorraine.fr/lue/ )
Contract period: 36 months
Expected date of employment: October 2022
Proportion of work: Full time
Desired level of education: Master’s degree in physics, material science or nanophysics.

 

Subject description

 

The digital data generated annually around the world is now counted in zettabytes, or trillions of billions of bytes. This is equivalent to delivering hundreds of millions of books of data every second. The amount of data generated continues to grow because of the developpement of “Internet of Things”, “Autonomous Driving” , “ Artificial Intelligence” etc … . Its growth is so strong that if the same technologies continued to be used, by 2040 all of the current global electricity consumption would be devoted to data storage.

 

Spin-based rather than charge-based logic is in principle faster and more energy efficient, which might offer a solution to the handling of the exponential increase in data traffic. Superconductivity, on the other hand, allows zero-dissipation charge transport and the introduction of superconducting circuitry might considerably reduce the energy load associated to data traffic.  Recent theoretical and experimental works have shown that the introduction of superconducting elements in spin-based devices can significantly boost their performance for logic operation. One example of how superconducting order can enhance conventional spintronics is in the superconducting analogue of a giant magnetoresistance junction. The substitution of the metallic spacer between the two ferromagnets with a superconductor has been shown to lead to potentially much higher resistance changes. Moreover, quasiparticles in the superconducting state have been shown to have spin relaxation times that exceed those of normal metals by several orders of magnitude, in principle allowing for much more effective spin transport.

 

This project aims at joining the expertise of two groups at Cavendish laboratory  in Cambridge University, and one group at institut Jean Lamour in Université de Lorraine to investigate how spin transport in superconducting spintronic heterostructures scale in the picosecond regime, comparable to the relaxation times of quasiparticles. Previous experiments have broadly focused on the DC limit whereas the experiments that we propose here are very timely and essential for accessing the potential for the implementation of ultra-fast device functionalities.

 

Keywords: Spin current, Superconductivity, antiferromagnet, spin-orbit torque, skyrmions.

 

 

 

 

Work context

The PhD student will work within the Spintronic and Nanomagnetism research group  https://spin.ijl.cnrs.fr  under the supervision of Stephane Mangin and within the Cavendish Laboratory under the supervision of Chiara Ciccarelli https://www.me.phy.cam.ac.uk/group-members/cc538%40cam.ac.uk

 

 

Skills

Knowledge of Solid State Physics, including magnetism and electronic transport properties and English (oral and written) is essential.

As an enthusiastic researcher you like team work, and have a flexible approach to collaborating between different laboratories.

Taste in both experimental and theoretical work.

 

Constraints and risks

No major risk.

 

About Institut Jean Lamour

 

The Institute Jean Lamour (IJL) is a joint research unit (UMR 7198) of CNRS and Université de Lorraine.

Focused on materials and processes, science and engineering, it covers: materials, metallurgy, plasmas, surfaces, nanomaterials and electronics. It regroups 183 researchers/lecturers, 91 engineers/technicians/administrative staff, 150 doctoral students and 25 post-doctoral fellows. Partnerships exist with 150 companies and our research groups collaborate with more than 30 countries throughout the world. Its exceptional instrumental platforms are spread over 4 sites; the main one is located on Artem campus in Nancy.

The project will be carried out within the SPIN team https://spin.ijl.cnrs.fr  whose subjects range from the development of innovative materials for implementation in spin electronics devices, to the development of magnetic sensors and the fundamental study of physical phenomena related to magnetism.

 

Application

Application should be performed trough adum.fr   

By email, please use the following subject:

“NAME application for LUE PhD 2022” where NAME stands for your last name.

Applicants are invited to send a CV and cover letter together with diploma copies to:

 

·             Stéphane Mangin (Lorraine University ) : stephane.mangin@univ-lorraine.fr

Chiara Ciccarelli (Cambridge University): cc538@cam.ac.uk

DESCRIPTION

Picosecond spin electronics is an emerging field of research that exploits ultrashort (picosecond) wide electrical pulses to manipulate and detect the magnetization of samples, in order to develop new ultrafast methods for information manipulation. The project will be based on a unique femtosecond laser-based setup, that allows the generation of such ultrashort electrical pulses (see our recent Nature Electronics publication). This setup will be used to test and characterize a number of spin transport effects, on various materials, at various time-scales. The project will be carried in collaboration with various partners, including UC Berkeley and UC San Diego.

 

JOB LOCATION: 

This 36 months position will be based at Institut Jean Lamour (Université de Lorraine).The PhD student will join the SPIN (Spintronic & Nanomagnetism) team, a group of 15 permanent academics and researchers, 20 Master and PhD students and 15 Post-doc and visitors, lead by Jon Gorchon. During her or his PhD the candidate will collaborate and may visit the groups of Jeffrey Bokor from UC Berkeley (California) and Eric Fullerton from UC San Diego (California).

The target start date for the position is October 1st 2021, with
some flexibility on the exact start date.

HOW TO APPLY

We are trying to find a candidate quickly. Deadline for application is Mai 1st 2021. Applicants are requested to submit the following materials:

• A cover letter applying for the position

• Full CV and list of publications

• Academic transcripts

• A few references (teachers, advisors…), if available

Applications and questions about the position can be sent to Jon Gorchon

DESCRIPTION

Ultrafast spin electronics is an emerging field of research that combines the ideas and concepts of magneto-optics and opto-magnetism with spin transport phenomena, supplemented with the possibilities offered by photonics for ultrafast low-dissipative manipulation and transport of information. Both light and spin currents can control magnetic order, though the mechanisms as well as the corresponding time scales and energy dissipations differ. The project aims at the best of both worlds, combining short time scales and non-dissipative propagation of light pulses with nanoscale selectivity and strong interactions of spin currents, to create novel concepts for data technology. The ultimate
goals are the creation and implementation of non-volatile, low-dissipative, and ultrafast functional elements. To reach these goals, the candidate will be working on a project lead by two groups in two different university (Université de Lorraine in France and Tohoku University in Japan); the two groups have complementary skills and backgrounds.

 

JOB LOCATION: 

This 36 months position will be based at Institut Jean Lamour (Université de Lorraine).The PhD student will join the SPIN (Spintronic & Nanomagnetism) team, a group of 15 permanent academics and researchers, 20 Master and PhD students and 15 Post-doc and visitors, lead by Stephane Mangin. During her or his PhD the candidate will visit and collaborate with the group of Shunsuke Fukami.

The target start date for the position is October 1st 2020, with
some flexibility on the exact start date.

HOW TO APPLY

Deadline for application is September 1st 2020. Applicants are requested to submit the following materials:

• A cover letter applying for the position

• Full CV and list of publications

• Academic transcripts

 

Applications and questions about the position can be sent to Stéphane Mangin (Stephane.mangin@univ-lorraine.fr

COMRAD is an H2020 ITN project (2020-2024). It will explore novel routes for the fastest possible and least dissipative magnetic switching in random access devices by bringing together the two disciplines of ultrafast magnetism and spinorbitronics, creating sub-100 ps stimuli in spinorbitronics and pushing the latter into a regime beyond the limitations of equilibrium thermodynamics.

The ambition of COMRAD is to train PhDs in such a way that they gain a broad understanding of the challenges in the entire process of emergence and development of opto-magnetic data storage, from fundamental research to device and failure analysis.

MAIN OBJECTIVES: We want to investigate ultrafast dynamics of transport properties in magnetic multilayers including those with ferrimagnetic GdFeCo as the storage layer in order to control and optimize its dynamics. (i) We will first strive for controlling and optimizing the generation of an optically generated spin current and the resulting ultrafast switching on a storage layer. (ii) We will seek for revealing the fundamental limits on the speed of writing.

JOB LOCATION: This 36 months position will be based at Institut Jean Lamour (Université de Lorraine). The PhD student will join the SPIN ( Spintronic & Nanomagnetism) team, group of 15 permanent academics and researchers, 20 Masters and PhD students and 15 Post-doc and visitors. https://spin.ijl.cnrs.fr

Stéphane Mangin will be your PhD advisor 

The target start date for the position is October 1st 2020, with some flexibility on the exact start date. 

HOW TO APPLY: Deadline for application is September 1st 2020. See details on https://comrad-etn.eu/jobs/ Applicants are requested to submit the following materials:

• A cover letter applying for the position 

• Full CV and list of publications 

• Academic transcripts 

Applications and questions about the position can be sent to Stéphane Mangin (stephane.mangin@univ-lorraine.fr).