Highly Efficient Spin-to-Charge Current Conversion in Strained HgTe Surface States Protected by a HgCdTe Layer

P. Noel (1) , C. Thomas (2) , Y. Fu (1) , L. Vila (1) , B. Haas (3) , Pierre-Henri Jouneau (3) , S. Gambarelli (4) , Tristan Meunier (5) , P. Ballet (2) , J. P. Attané (1)

1 SPINTEC - SPINtronique et TEchnologie des Composants
2 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information
3 LEMMA - Laboratoire d'Etude des Matériaux par Microscopie Avancée
4 CAMPE - Conception d’Architectures Moléculaires et Processus Electroniques
5 NEEL - QuantECA - Circuits électroniques quantiques Alpes

We report the observation of spin-to-charge current conversion in strained mercury telluride at room temperature, using spin pumping experiments. The conversion rates are found to be very high, with inverse Edelstein lengths up to 2.0 +/- 0.5 nm. The influence of the HgTe layer thickness on the conversion efficiency has been studied, as well as the role of a HgCdTe barrier inserted in-between the HgTe and NiFe layers. These measurements, associated to the temperature dependence of the resistivity, allows to ascribe these high conversion rates to the spin momentum locking property of HgTe surface states.

Domaines: Matière Condensée [cond-mat]

P. Noel, C. Thomas, Y. Fu, L. Vila, B. Haas, et al.. Highly Efficient Spin-to-Charge Current Conversion in Strained HgTe Surface States Protected by a HgCdTe Layer. Physical Review Letters, 2018, 120 (16), pp.167201. ⟨10.1103/PhysRevLett.120.167201⟩. ⟨hal-01614284⟩