Electrical Initialization of Electron and Nuclear Spins in a Single Quantum Dot at Zero Magnetic Field.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 29517243.
- Also identified by DOI 10.1021/acs.nanolett.7b05351.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
The emission of circularly polarized light from a single quantum dot relies on the injection of carriers with well-defined spin polarization. Here we demonstrate single dot electroluminescence (EL) with a circular polarization degree up to 35% at zero applied magnetic field. The injection of spin-polarized electrons is achieved by combining ultrathin CoFeB electrodes on top of a spin-LED device with p-type InGaAs quantum dots in the active region. We measure an Overhauser shift of several microelectronvolts at zero magnetic field for the positively charged exciton (trion X<sup>+</sup>) EL emission, which changes sign as we reverse the injected electron spin orientation. This is a signature of dynamic polarization of the nuclear spins in the quantum dot induced by the hyperfine interaction with the electrically injected electron spin. This study paves the way for electrical control of nuclear spin polarization in a single quantum dot without any external magnetic field.