Generation and control of polarization-entangled photons from GaAs island quantum dots by an electric field.
Semiconductor quantum dots are potential sources for generating polarization-entangled photons efficiently. The main prerequisite for such generation based on biexciton-exciton cascaded emission is to control the exciton fine-structure splitting. Among various techniques investigated for this purpose, an electric field is a promising means to facilitate the integration into optoelectronic devices. Here we demonstrate the generation of polarization-entangled photons from single GaAs quantum dots by an electric field. In contrast to previous studies, which were limited to In(Ga)As quantum dots, GaAs island quantum dots formed by a thickness fluctuation were used because they exhibit a larger oscillator strength and emit light with a shorter wavelength. A forward voltage was applied to a Schottky diode to control the fine-structure splitting. We observed a decrease and suppression in the fine-structure splitting of the studied single quantum dot with the field, which enabled us to generate polarization-entangled photons with a high fidelity of 0.72 ± 0.05.
Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan.
Mohsen
M
Ghali
Keita
K
Ohtani
Yuzo
Y
Ohno
Hideo
H
Ohno
D001152:Arsenicals / Q000737:chemistry*; D004560:Electricity; D004581:Electronics; D005708:Gallium / Q000737:chemistry*; D008027:Light; D036103:Nanotechnology / Q000379:methods; D009991:Oscillometry / Q000379:methods; D017785:Photons; D010825:Physics / Q000379:methods; D045663:Quantum Dots; D012542:Scattering, Radiation; D012666:Semiconductors; D013053:Spectrophotometry / Q000379:methods; D013997:Time Factors
D001152:Arsenicals; C043055:gallium arsenide; D005708:Gallium