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

P Noel; C Thomas; Y Fu; L Vila; B Haas; P-H Jouneau; S Gambarelli; T Meunier; P Ballet; J P Attané

doi:10.1103/PhysRevLett.120.167201

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

Phys Rev Lett. 2018 Apr 20;120(16):167201. doi: 10.1103/PhysRevLett.120.167201.

Authors

P Noel¹, C Thomas², Y Fu¹, L Vila¹, B Haas³, P-H Jouneau³, S Gambarelli⁴, T Meunier⁵, P Ballet², J P Attané¹

Affiliations

¹ Univ. Grenoble Alpes, CEA, CNRS, Grenoble INP, INAC, SPINTEC, F-38000 Grenoble, France.
² Univ. Grenoble Alpes, CEA, LETI, MINATEC Campus, F38054 Grenoble, France.
³ CEA, INAC-MEM, 38054 Grenoble, France.
⁴ CEA, Institut Nanosciences et Cryogénie, SyMMES F-38000 Grenoble, France.
⁵ CNRS, Institut NEEL, 38042 Grenoble, France.

PMID: 29756906
DOI: 10.1103/PhysRevLett.120.167201

Abstract

We report the observation of spin-to-charge current conversion in strained mercury telluride at room temperature, using spin pumping experiments. We show that a HgCdTe barrier can be used to protect the HgTe from direct contact with the ferromagnet, leading to very high conversion rates, with inverse Edelstein lengths up to 2.0±0.5 nm. The influence of the HgTe layer thickness on the conversion efficiency is found to differ strongly from what is expected in spin Hall effect systems. These measurements, associated with the temperature dependence of the resistivity, suggest that these high conversion rates are due to the spin momentum locking property of HgTe surface states.