Probing the helical edge states of a topological insulator by Cooper-pair injection

Pierre Adroguer (1) , Charles Grenier (1) , David Carpentier (1) , Jérome Cayssol (2) , Pascal Degiovanni (1) , Edmond Orignac (1)

1 Phys-ENS - Laboratoire de Physique de l'ENS Lyon
2 CPMOH - Centre de physique moléculaire optique et hertzienne

We consider the proximity effect between a singlet s-wave superconductor and the edge of a quantum spin Hall (QSH) topological insulator. We establish that Andreev reflection at a QSH edge state/superconductor interface is perfect while nonlocal Andreev processes through the superconductor are totally suppressed. We compute the corresponding conductance and noise.

Mots clés: topological insulators; supraconductivity; quantum Hall effect; quantum transport

Domaines: Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]

Pierre Adroguer, Charles Grenier, David Carpentier, Jérome Cayssol, Pascal Degiovanni, et al.. Probing the helical edge states of a topological insulator by Cooper-pair injection. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2010, 82 (8), pp.081303(R). ⟨10.1103/PhysRevB.82.081303⟩. ⟨ensl-00517370⟩