Groupe de Physique Statistique

Equipe 106, Institut Jean Lamour

                     
Accueil
Accès
Personnel
Publications
Séminaires
Chronologique
par Orateurs
Ateliers
Rencontres
Ecoles
International
Grp Travail
Theses, Postes
Enseignement

Séminaire de groupe

Graphene Induced Topological Insulator (Topological order and Superconductivity)
Cyril Petitjean
jeudi 17 janvier 2013 , 14h00
Salle de séminaire du groupe de Physique Statistique

Two-dimensional topological insulators are commonly referred to as quantum spin-Hall (QSH) states [1]. Contrary to the three-dimensional topological insulators that have been found to abound in nature, the twodimensional are rather limited. However recently a spin-orbit induced QSH phase has been proposed [2]. The key ingredient is the use of indium adatoms deposited on the surface of graphene thats should turn the latter into a QSH insulator characterized by a sizable gap. This artificial QSH system present strong potentials applications for thermopower [3] or spintronics [4] devices. One interesting fact about indiums is that the latter becomes superconductor at low enough temperature, Therefore the graphene+indium artificial QSH system becomes a promising candidate to study the competition between induced superconductivity and the spin-orbit coupling [5]. In this talk, we will first give a short introduction on the two-dimensional topological insulators and the related artificial QSH system. We will then present how such setup can naturally provides a spin-polarized current switch [4]. We finally turn on the superconducting order and spin-orbit competition. We show that starting form a general superconducing plaquette interaction, the latter can be reduced to a simpler effective model. This permit us to determine the first preliminary phase diagram [5]. <br> [1] C. L. Kane and E. J. Mele, Phys. Rev. Lett. 95, 226801 (2005). <br> [2] C.Weeks, J. Hu, J. Alicea, M. Franz, and R. Wu, Phys. Rev. X 1, 021001 (2011) <br> [3] O. Shevtsov, P. Carmier, C. Groth, X. Waintal, and D. Carpentier, Phys. Rev. B 85, 245441 (2012). <br> [4] O. Shevtsov, P. Carmier, C. Petitjean,C. Groth, X. Waintal, and D. Carpentier, Phys. Rev. X 2, 031004 (2012). <br>[5] C. Petitjean, E. Orignac and D. Carpentier in preparation

Fichier PDF


Haut de page