PhD subjects

Dernière mise à jour : 21-10-2017

5 sujets INAC

• Electronics and microelectronics - Optoelectronics

• Solid state physics, surfaces and interfaces

• Thermal energy, combustion, flows

 

MRAM-based synchronous integrated circuit design on advanced technology node for space applications

SL-DRF-18-0178

Research field : Electronics and microelectronics - Optoelectronics
Location :

Spintronique et technologie des composants (SPINTEC)

Laboratoire Spintec (SPINTEC)

Grenoble

Contact :

Gregory DI PENDINA

Lionel TORRES

Starting date : 01-10-2018

Contact :

Gregory DI PENDINA

CEA - DSM/INAC/SPINTEC/SPINTEC

0438784746

Thesis supervisor :

Lionel TORRES

Université de Montpellier - LIRMM

04 67 41 85 67

Personal web page : http://inac.cea.fr/Pisp/gregory.dipendina/index.html

Laboratory link : http://www.spintec.fr/

Nowadays, there are several methods to design microelectronics circuits adapted to space applications, meeting the radiation hardening constraints, using specific techniques or fabrication processes. After a

3 year strong and rich experience in the framework of a Ph. D. in collaboration with CNES, LIRMM and CEA/Spintec, from 2014 to 2017, we would like to expand and reinforce this work. We want to propose novel design architectures embedding emerging non volatile technologies, such as spintronics using MRAM (magnetic memories), for harsh environment, especially for space. Several study have already been done or are currently ongoing on MRAM memories. However, we propose here to integrate MTJ (magnetic Tunnel Junctions), basic element of MRAM, into the computational logic. These MTJs can be used in sequential parts such as flip-flop and latches, or into cells such as NAND, NOR, etc. The final aim is to propose an hybrid CMOS/MRAM logic to harden integrated circuits against space environment. This subject addresses computational digital circuits such as microprocessors for instance. Moreover, STT-MRAM (Spin Transfer Torque) which is the most advanced MRAM technology which start to be commercialized will be used for this work.

On the other hand, the SOT-MRAM (Spin Orbit Torque) technology which is the most emerging MRAM one will also be considered in order to provide the most complete study and the most efficient solution. This work is very prospective and will use very advanced CMOS process. The goal is to fabricate a complete demonstrator and to perform functional and radiation tests with the CNES to validate the robustness of such an approach CMOS/MRAM against particle strikes. This Ph. D. would be mainly co-supervised by the Spintronics IC design team at CEA/Spintec Grenoble and supervised by LIRMM - Montpellier.

Theoretical study of advanced magnetocaloric materials

SL-DRF-18-0177

Research field : Solid state physics, surfaces and interfaces
Location :

Photonique, Electronique et Ingénierie Quantiques (PHELIQS)

Groupe Théorie (GT)

Grenoble

Contact :

Mike ZHITOMIRSKY

Starting date : 01-10-2018

Contact :

Mike ZHITOMIRSKY

CEA - DRF/INAC/PHELIQS/GT

0438784330

Thesis supervisor :

Mike ZHITOMIRSKY

CEA - DRF/INAC/PHELIQS/GT

0438784330

Laboratory link : http://inac.cea.fr/Phocea/Vie_des_labos/Ast/ast_groupe.php?id_groupe=1157

An external magnetic field affects the entropy of a magnetic system and provokes temperature variations which can be used for magnetic refrigeration. Such an alternative cooling technology is increasingly important nowadays for space telescopes, particle physics experiments and quantum computing. The existing adiabatic demagnetization refrigerators utilize paramagnetic salts, which have limited capacity for temperatures above 1 K. Recently, two new families of magnetocaloric materials suitable for applications in the 1-4 K temperature range have been proposed: geometrically frustrated spin systems and dipolar magnets. We plan to study the magnetocaloric properties of such materials using large scale Monte Carlo simulations of realistic spin models appropriate for the known, Gd3Ga5O12 and GdLiF4, as well as for the prospective, Yb2Ti2O7 and Yb3Ga5O12, magnetocaloric materials. The theoretical study will benefit from a collaboration with the on-going experimental work at INAC.

Manipulation of spin currents and magnetic state at the nanoscale using the spin orbit coupling

SL-DRF-18-0058

Research field : Solid state physics, surfaces and interfaces
Location :

Spintronique et technologie des composants (SPINTEC)

Laboratoire Spintec (SPINTEC)

Grenoble

Contact :

Laurent VILA

Jean Philippe ATTANE

Starting date : 01-10-2018

Contact :

Laurent VILA

CEA - DSM/INAC/SP2M/NM

0438780355

Thesis supervisor :

Jean Philippe ATTANE

Universite Joseph Fourier - INAC/SP2M

0438784326

Personal web page : http://inac.cea.fr/Pisp/laurent.vila/

Laboratory link : http://www.spintec.fr/research/spin-orbitronics/

The development of spin electronics, or spintronics, allows to imagine many devices taking advantage of an electronics no longer based solely on the electrical charge of the carriers but also on their spin. This new degree of freedom offers additional means of conveying information, and introduces new ways to manipulating it.

Very recently, a collection of Spin Orbit based spin- to-charge interconversion mechanisms (Spin Hall effects, Rashba and Topological Insulators) were observed experimentally. It appears in the set of non-magnetic metals, semiconductors or oxydes, and sorts the carriers according to their spin state. It allows injecting and detecting spins without necessarily using magnetic materials or a magnetic field, which is both conceptually and technologically very interesting.

In this framework, we wish to create lateral nanostructures taking advantage of pure spin current generated by harnessing the Spin Orbit coupling for both spin to charge interconversion mechanisms and the manipulation of magnetization state of nano-object (dot or magnetic domain wall) by absorption of this current and spin transfer torque. Material of interest will be metals, oxydes and topological insulators to generate or detect spin currents, and will be applied to the manipulation of the magnetic state of a nanoelement, an example of a recent realization being given on the figure.

If subjects related to the spin transfer by absorption of a pure spin current are very competitive, they are scientifically rich, and currently booming. This area of research is still largely open to exploration, and we are benefiting from our recent development of efficient injection and detection devices.

The proposed topic lies in basic research but with a clear opening towards applied research. The trainee will benefit from the technical and scientific environment of the laboratory, and the collaborations put in place with the major actors of the field at the international level. This project is supported by funding from the ANR.

Miniature and ultra-sensitive magnetometer for space missions

SL-DRF-18-0141

Research field : Solid state physics, surfaces and interfaces
Location :

Spintronique et technologie des composants (SPINTEC)

Laboratoire Spintec (SPINTEC)

Grenoble

Contact :

Hélène BEA

Claire BARADUC

Starting date : 01-10-2018

Contact :

Hélène BEA

UJF - DRF/INAC/SPINTEC

04 38 78 08 46

Thesis supervisor :

Claire BARADUC

CEA - DRF/INAC/SPINTEC/SPINTEC

04 38 78 42 35

Laboratory link : http://www.spintec.fr/research/magnetic-sensors/

The aim is to develop a miniature and ultra-sensitive magnetometer (100 fT / Hz^1/2), using magnetic tunnel junctions and microfabrication techniques from microelectronics. This magnetometer could replace the magnetometers currently used on space missions with a mass reduction by a factor of 100. This extreme lightness (~ 1 g without electronics) would represent a competitive advantage over inductive sensors currently used in space missions (mass > 1 kg).

The proposed magnetometer combines a magnetic tunnel junction as sensing element of the sensor, a flux concentrator to amplify the field to be measured, and a magnetic field modulation system to reduce the noise of the measurement. Preliminary studies have shown the feasibility of the basic bricks of this sensor. It is now necessary to optimize the flux concentrator and the magnetic tunnel junction, in particular by developing an innovative junction that is currently the subject of a patent application.

The thesis work will mainly be experimental (microfabrication, electrical and magnetic characterization, noise measurements, magnetic imaging) but will also include analysis and micromagnetic simulations.

Inertial Confinement and Centimetric Cavity Collapse

SL-DRF-18-0218

Research field : Thermal energy, combustion, flows
Location :

Service des Basses Températures (SBT)

Laboratoire Cryogénie Fusion (LCF)

Grenoble

Contact :

Jérome DUPLAT

Starting date : 01-09-2017

Contact :

Jérome DUPLAT

Université Grenoble Alpes - DRF/INAC/SBT/LCF

04 38 78 64 89

Thesis supervisor :

Jérome DUPLAT

Université Grenoble Alpes - DRF/INAC/SBT/LCF

04 38 78 64 89

In the frame of the research on the inertial confinement to obtain the nuclear fusion, we intend to study the collapse dynamics of large nearly-void spherical bubble inside a liquid, provoking the inertial confinement of the matter trapped inside the cavity.

This process is similar to sonoluminescence experiment or to inertial confinement fusion experiement. However, our original setup allows to work at larger length and time scales,

and then allow the direct observation of all thermodynamical and hydrodynamical phenomena.



Preliminar experiments indicates that temperature higher than 20000 K can be reached, and maybe much more.



The experimental work will be a base for developing physical models.

 

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