2D SPINTRONICS

Overview

The « 2D spintronics » team deals with spin dependent phenomena in two important classes of materials: Si and Ge which are the materials of today’s microelectronics and transition metal dichalcogenides which are emerging 2D materials with exceptional optical and spin-orbit properties. We are studying model systems grown by molecular beam epitaxy and their spin properties.

Research topics

Magnetism induced by manganese doping in germanium

(2005-present). Manganese doped germanium films grown by molecular beam epitaxy undergo a nanospinodal decomposition: the system spontaneously decompose into Mn-rich areas like nanocolumns. Our research focuses on the atomic, electronic structure and magnetic properties of these nanosized Mn-rich areas. We also investigate their coupling with charge carriers to induce novel magneto-transport properties.

Spin injection in silicon and germanium

(2011-present). The original goal of this topic is to build the spin field-effect-transistor (FET) made of silicon and germanium. For this purpose, we study the microscopic mechanism of electrical spin injection in Si and Ge using three-terminal devices and lateral spin valves. In particular, we have investigated the influence of interface states in the mechanism of spin injection from a magnetic tunnel junction into Si and Ge. However the missing ingredient to build the spin-FET is a sizeable spin-orbit coupling to manipulate the spin state by electric fields.

Spin-orbit effects in silicon and germanium

(2013-present). Si and Ge exhibit low bulk spin-orbit coupling and we take advantage of metal/Si and metal/Ge interfaces to create a large Rashba spin-orbit coupling to manipulate the electron spin state. Moreover, the same Rashba spin-orbit interaction can be used to generate and detect spin currents in silicon or germanium by spin-to-charge interconversion. Another class of materials we use for spin-to-charge interconversion are topological insulators like the alpha phase of tin. In these materials, spin-to-charge conversion occurs at the surface or interface: by growing these materials onto Si or Ge we aim at transferring the spin-to-charge interconversion into the semiconductor.

Van der Waals epitaxy of transition metal dichalcogenides (TMDs) for spintronics

(2015-present). The goal of this topic is the growth of single crystalline TMDs over large areas (typically cm2) for both the study of spin dependent phenomena like spin valleytronics and for the development of new 2D spintronic devices. For this purpose, we use single crystalline substrates and the van der Waals epitaxy in a molecular beam epitaxy machine. Our efforts then focus on electrical and magnetic doping as well as on the growth of heterostructures.

The team

Former members

Post-docs

Minh-Tuan DAU (2016-2017)

PhD

Fabien RORTAIS (2013-2016)

Internships

Takeo KOIKE (Sept.-Nov. 2017)

Projects

ANR MAGICVALLEY (2018-2021)
ANR GEMO (2008-2010)
RTRA IMAGE (2009-2011)
ANR SiGeSPIN (2014-2017)
ANR MoS2ValleyControl (2015-2017)
ANR TOP-RISE (2017-2020)
Projet Phare CEA DRF-DRT 2D Factory (2015-2019)
Projet CARNOT H2D3D (2017-2019)

Recent news

PhD defense – Utilisation du couplage spin-orbite dans le germanium pour la génération, la détection et la manipulation du spin. (September 16th, 2020)
Vendredi 16 Octobre 2020 à 14H00, Thomas Guillet soutiendra sa thèse, intitulée : Utilisation du couplage spin-orbite dans le germanium pour la génération, la détection et la manipulation du spin Lieu : CEA, Bat 10.05 auditorium 445 ...
Masters thesis projects for Spring 2021 (September 15th, 2020)
You find here the list of proposals for Master-2 internships to take place at Spintec during Spring 2021. In most cases, these internships are intended to be suitable for a longer-term PhD work. Interested Master-1 ...
PhD defense – Optimisation de la croissance de MoSe2 – WSe2 par épitaxie de van der Waals pour la valleytronique (September 14th, 2020)
Vendredi 02 Octobre 2020 à 14H00, Céline Vergnaud soutiendra sa thèse, intitulée : Optimisation de la croissance de MoSe2 – WSe2 par épitaxie de van der Waals pour la valleytronique Lieu : bâtiment GreEn-ER de l’Ecole Grenoble ...
Spin-orbitronics at a topological insulator-semiconductor interface (July 02nd, 2020)
Topological insulators (TI) represent a new class of insulating materials hosting metallic surface states. Moreover, those surface states exhibit a Dirac cone energy dispersion where the strong spin-orbit coupling leads to a helical spin texture ...
Observation of Large Unidirectional Rashba Magnetoresistance in Ge(111) (March 10th, 2020)
Relating magnetotransport properties to specific spin textures at surfaces or interfaces is an intense field of research nowadays. Here, we investigate the variation of the electrical resistance of Ge(111) under the application of an external ...