2009/01/29 by Kushal C. Wijesundara, Mauricio Garrido, Wijesundara, Kushal C. +11
Physics and Astronomy · Materials Science · #Semiconductor Quantum Structures and Devices #Quantum and electron transport phenomena #Quantum Dots Synthesis And Properties
paper · pdf · doi:10.48550/arxiv.0901.4751
Spin manipulation in coupled quantum dots is of interest for quantum information applications. Control of the exchange interaction between electrons and holes via an applied electric field may provide a promising technique for such spin control. Polarization dependent photoluminescence (PL) spectra were used to investigate the spin dependent interactions in coupled quantum dot systems and by varying an electric field, the ground state hole energy levels are brought into resonance, resulting in the formation of molecular orbitals observed as anticrossings between the direct and indirect transitions in the spectra. The indirect and direct transitions of the neutral exciton demonstrate high and low circular polarization memory respectively due to variation in the exchange interaction. The ratio between the polarization values as a function of electric field, and the barrier height was measured. These results indicate a possible method of tuning between indirect and direct configurations to control the degree of exchange interaction.