Individual Cr atom in a semiconductor quantum dot: Optical addressability and spin-strain coupling

Alban Lafuente-Sampietro (1) , H. Utsumi (2) , Hervé Boukari (1) , Shinji Kuroda (2) , Lucien Besombes (1)

1 NEEL - NPSC - Nanophysique et Semiconducteurs
2 Université de Tsukuba = University of Tsukuba

We demonstrate the optical addressability of the spin of an individual chromium atom (Cr) embedded in a semiconductor quantum dot. The emission of Cr-doped quantum dots and their evolution in magnetic field reveal a large magnetic anisotropy of the Cr spin induced by local strain. This results in the zero field splitting of the 0, ±1, and ±2 Cr spin states and in a thermalization on the magnetic ground states 0 and ±1. The observed strong spin to strain coupling of Cr is of particular interest for the development of hybrid spin-mechanical devices where coherent mechanical driving of an individual spin in an oscillator is needed. The magneto-optical properties of Cr-doped quantum dots are modeled by a spin Hamiltonian including the sensitivity of the Cr spin to the strain and the influence of the quantum dot symmetry on the carrier-Cr spin coupling.

Domaines: Autre [cond-mat.other]

Alban Lafuente-Sampietro, H. Utsumi, Hervé Boukari, Shinji Kuroda, Lucien Besombes. Individual Cr atom in a semiconductor quantum dot: Optical addressability and spin-strain coupling. Physical Review B, 2016, 93 (16), pp.161301(R). ⟨10.1103/PhysRevB.93.161301⟩. ⟨hal-01302677⟩