PHD offer : Spintronic transmitters for Terahertz

29 Apr 2024
Job Information

Organisation/Company

IEMN-CNRS

Department

AIMAN-FILMS

Research Field

Physics » Applied physics
Physics » Electromagnetism
Physics » Optics

Researcher Profile

First Stage Researcher (R1)

Country

France

Application Deadline

13 May 2024 - 13:00 (Europe/Paris)

Type of Contract

Temporary

Job Status

Full-time

Offer Starting Date

1 Sep 2024

Is the job funded through the EU Research Framework Programme?

Not funded by an EU programme

Is the Job related to staff position within a Research Infrastructure?

No

Offer Description

IEMN is a major player in micro/nanotechnologies and their applications. With more than 450 employees of 40 different nationalities, IEMN brings together most of the research in Hauts-de-France, from nanoscience to instrumentation in the field of micro-nano-technology. With a budget of €28 million, 5 supervisory bodies (CNRS, University of Lille, University Polytechnique Hauts-de-France, Centrale Lille, Junia), 1600 square meters of clean rooms, two certified micro-nano-fabrication and multi-physics characterization platforms, IEMN develops high value-added miniaturized technologies in electronics, photonics, quantum technologies, telecommunications, health technologies, electrical energy, the Internet of Things and transportation.

As part of the national PEPR SPIN project and in particular the targeted TOAST project, the IEMN is working on the development and study of spintronic THz emitters (STE).

Background to the proposed work: Scientific work on THz took off in the 1980s with the discovery by Auston, at Bell Labs, of the photoconductive switch, also known as the "Auston Switch". Since then, THz research has developed only slowly, and few applications exist despite the frequency band's enormous potential. This is partly due to the many challenges in the field of sources, waveguides and detectors. One of these major challenges is the 5-12 THz frequency band, for which there is as yet no suitable source. Proposed in 2016 by Seifert et al[1], spintronic transmitters form the link between spintronics and THz photonics. Thanks to spin transport phenomena combined with the use of ultra-short femtosecond laser pulses, these emitters enable the generation of electromagnetic pulses in the THz range with a very broad spectrum from THz to 30THz, which is extremely interesting for imaging, spectroscopy or ellipsometry characterisation applications. Following the 2016 article, there has been a great deal of interest in this subject, which has been the subject of a great deal of research and development, particularly at the IEMN. Among other things, we have demonstrated two original techniques for controlling the polarization of the THz signal [2-9]. Our article on the demonstration of magnetoelectric control was selected for the cover of Applied Physics Letters.

More recently, we have been working with the Fraunhofer ITWM institute in Kaizerslautern on the integration of transmitters on optical fibres [10]. The IEMN's collaborations on this subject include teams from the ENS Physics Laboratory, the CNRS-Thalès joint unit (Albert FERT Laboratory) and the VSB in Ostrava in the Czech Republic.

Purpose of the thesis :

The field of spintronic emitters is booming, and there are still many aspects to be explored, in particular aspects of emission control by energy-efficient means, or exploring the possibilities of texturing these emitters, or integrating them into complex micro-devices.

In particular, achieving ultrafast modulation of spin-based THz transmitters would further enhance their potential for integration into THz technologies. To this end, we plan to use spintronic THz transmitters with magneto-elastic properties. For example, we have demonstrated the special properties of magnetoelastic [TbCo2 /FeCo]xN multilayers exhibiting in-plane uniaxial magnetic anisotropy. These properties will form the basis of our work on ultrafast modulation. Thanks to the mastery of magnetic anisotropy properties, these stacks allow a controllable spin reorientation transition (SRT), offering very high magnetic sensitivity with respect to the external magnetic field, and in a frequency range of up to several GHz [11]. High-speed modulation will be induced using FMR-like techniques.

In addition, large magnetostriction allows effective control of spin direction via a strain-induced magnetoelectric effect, when combined with electro-active materials such as piezoelectrics or PMN-PT ferroelectric relaxers. This concept has already been successfully exploited by the IEMN for quasi-static magnetoelectric control of the polarisation of the THz signal emitted in spintronic transmitters [5], but one of the aims of the thesis work will be to study an increase in frequency. In particular, magnetisation can be controlled at high frequencies by integrating the emitters with surface acoustic wave (SAW) devices, in which the IEMN also has considerable expertise. In devices such as the SAW delay lines already built at the IEMN, this will result in dynamic control of the strain, leading to high-speed modulation of the THz signal. For these devices, the aim of the work will be to present a versatile spintronic THz transmitter whose specifications can be tailored to specific needs (wide/narrow band, modulation speed, bias control, minimum power levels in specific bands, etc.).

The work will therefore potentially be highly multidisciplinary, ranging from theoretical aspects to the development and characterisation of demonstrators, via finite element simulations, the deposition and characterisation of magnetic layers by cathode sputtering, the production of emitters and structuring in a clean room, and involvement in setting up TDS measurement benches with automation (Labview or preferably Python).

Depending on the results obtained in the initial phases, the aim will be to develop a specific application of interest, either in spectroscopy, ellipsometry or telecommunications.

From the technological developments prospective : the person recruited will be able to benefit from the equipment and skills of the IEMN's micro and nanofabrication centre (CMNF) (https://www.iemn.fr/les_plateformes /cmnf ), one of the major technology centres in the RENATECH network. The laboratory also has extensive experience and an international reputation in the field of THz. Here again, the laboratory has a large platform dedicated to DC characterisation up to THZ (https://www.iemn.fr/ les_plateformes/plateforme-de-caracterisation-multi-physique-pcmp/ caracterisation-haute-frequence  ).

Finally, in this context, the person recruited for this doctoral work will have to be involved and will lead some of the stages of the research work. He/she will also be fully involved in the ins and outs of the PEPR SPIN project and, as such, will be part of a high-level research consortium and will gain practical experience of the challenges of respecting research milestones and results, participating in consortium progress meetings and final review meetings.

 Sought Profile :

The candidate will hold an M2 Master's degree specialising in physics or electronics / micro-nano-systems.  Knowledge of magnetic and/or ferroelectric thin films is desirable. Experience of working in clean rooms is a plus, as is knowledge of spintronics and/or photonics. The person recruited should be able to work independently. As this is a relatively new field of research, candidates will be able to express their creativity.

Start of work :

As soon as possible (funding acquired) - subject to authorization by the Senior Defense Official. Average time taken to study the application: 2 months.

 

Information on life in Lille:

 https://www.expat.com/fr/guide/europe/france/lille/

 https://en.lilletourism.com/

 

 

Références (Références IEMN en couleur) :

[1] T. Seifert et al., “Efficient metallic spintronic emitters of ultrabroadband terahertz radiation”, Nature Photonics, volume 10, pages483–488 (2016)

[2] D. Khusyainov et al. , “Polarization control of THz emission using spin-reorientation transition spintronic heterostructure”, Scientific reports, 11(1), p657 (2021),  https://doi.org/10.1038/s41598-020-80781-5

[3] D. Khusyainov et al., "Increasing the efficiency of a spintronic THz emitter based on WSe2 /FeCo", Materials 14, 6479 (2021)

[4] S. Ovcharenko et al,” Ultrafast manipulation of magnetic anisotropy in a uniaxial intermetallic heterostructure TbCo2 /FeCo”, Journal of Physics D: Appl. Phys. 55, 175001(2022)

[5] G. Lezier et al., “Fully reversible magnetoelectric voltage controlled THz polarization rotation in magnetostrictive spintronic emitters on PMN-PT”, Appl. Phys. Lett. 120, 152404 (2022) - http://doi.org/10.1063/5.0080372 - arXiv:2112.00144 - HAL   11th April 2022 issue APL COVER.

[6] P. Kolejak et al., “360° polarization control of terahertz spintronic emitters using uniaxial FeCo/TbCo2 /FeCo trilayers”, ACS Photonics 2022, 9, 4, 1274–1285.  https://doi.org/10.1021/acsphotonics.1c01782 -  arXiv:2111.07118

[7] D. Khusyainov et al.,” Multiferroic THz emitter: Polarization control by electric field”, Physical Review Applied 17, 044025 (2022) - http://dx.doi.org/10.1103/PhysRevApplied.17.044025

[8] A. Buryakov et al., “The Role of Ferromagnetic Layer Thickness and Substrate Material in Spintronic Emitters”, Nanomaterials 13 (11), 1710 (2023) https://doi.org/10.3390/nano13111710

[9] A. M. Buryakov et al., "Efficient Co/Pt THz spintronic emitter with tunable polarization", Appl. Phys. Lett. 123, 082404 (2023), https://doi.org/10.1063/5.0160497

[10] F.Paries, N. Tiercelin, G. Lezier, M. Vanwolleghem, M-A Systaki, G. Jakob, M. Jourdan, M. Kläui, T. Kampfrath, T. Seifert, Z. Kaspar, G. Von Freymann and D. Molter, “Fiber-tip spintronic terahertz emitters”, Optics Express, 2023, 31 (19), pp.30884. https://doi.org/10.1364/OE.494623

[11] A. Klimov et al., Journal of Applied Physics,  107, 9 (2010) 093916-1-6

[12] A. Mazzamurro et al., “Giant Magnetoelastic Coupling in a Love Acoustic Waveguide Based on TbCo2 /FeCo Nanostructured Film on ST-Cut Quartz”, Physical Review Applied, 13, 044001 (2020) https://link.aps.org/doi/10.1103/PhysRevApplied.13.044001

Requirements

Research Field

Physics

Education Level

Master Degree or equivalent

Skills/Qualifications

The candidate will hold an M2 Master's degree specializing in physics or electronics / micro-nano-systems.  Knowledge of magnetic and/or ferroelectric thin films is desirable. Experience of working in clean rooms is a plus, as is knowledge of spintronics and/or photonics. The person recruited should be able to work independently. As this is a relatively new field of research, candidates will be able to express their creativity.

Level

Good

Additional Information
Work Location(s)

Number of offers available

1

Company/Institute

IEMN-CNRS

Country

France

State/Province

Hauts-de-France

City

Villeneuve d'Ascq

Postal Code

59652

Street

Cité scientifique

Geofield

Where to apply

E-mail

[email protected]

Contact

State/Province

Hauts-de-France

City

Villeneuve d Ascq

Website

https://www.iemn.fr

Street

Cité scientifique

Postal Code

59652

E-Mail

[email protected]

Phone

0320197946

STATUS: EXPIRED