An electrically injected quantum dot spin polarized single photon source

作者：Bhattacharya Pallab^*; Das Ayan; Basu Debashish; Guo Wei; Heo Junseok

来源：Applied Physics Letters, 2010, 96(10): 101105.

DOI：10.1063/1.3357426

The characteristics of an electrically injected spin polarized single photon source have been investigated. The GaAs-based microcavity diode consists of a single InAs/GaAs self-organized quantum dot as the single photon source and a MnAs/Al0.1Ga0.9As Schottky tunnel barrier for the ferromagnetic contact to inject spin polarized electrons. The measured output circular polarization of the biexciton emission at lambda similar to 1130 nm exhibits a switching behavior as a function of magnetic field, in the Faraday geometry, the value remaining near-zero for B < 1 T and similar to 6%-8% for B >= 1 T. The linear polarization shows a complementary trend. The results are explained in the framework of the exciton fine structure in the quantum dot and the effects of electron-hole exchange splitting, due to in-plane quantum dot anisotropy, and Zeeman splitting on the spin eigenstates and their coupling to the photon field.

• 出版日期2010-3-8