2015/04/03 by Haruki Kiyama, Takashi Nakajima, S. Teraoka +4
Engineering · Physics and Astronomy · #Advancements in Semiconductor Devices and Circuit Design #Atomic physics #Condensed matter physics #Electron #Excited state #Magnetic field #Ohmic contact #Optoelectronics #Physics #Quantum Hall effect #Quantum and electron transport phenomena #Quantum dot #Quantum mechanics #Quantum spin Hall effect #Semiconductor Quantum Structures and Devices #Spin (aerodynamics) #Spin Hall effect #Spin polarization #Spinplasmonics #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.91.155302
8 pages, 7 figures
arxiv created 2015/04/03 · openalex publication_date 2015/04/10 · arxiv updated 2015/06/24 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We report selective injection of both spin-up and spin-down single electrons into a quantum dot (QD) from spin-polarized nonequilibrium quantum Hall edge channels (ECs) generated by selective transmission of spin-resolved ECs using a surface gate placed at a distance from the QD. We change the spin polarization of nonequilibrium ECs by changing the bias voltages applied to different source Ohmic contacts. The efficiency of spin-up electron injection reaches 0.5, which is approximately 0.2 higher than that induced by spin-dependent tunnel coupling between QD and ECs. On the other hand, the efficiency of spin-down electron injection reaches 0.4. In addition, we rectify the underestimation of the efficiency of spin filtering for equilibrium ECs by numerically subtracting the contribution of the excited states in the QD. The obtained spin-filtering efficiency is higher than that evaluated from the raw experimental data and increases with magnetic field as expected with the increase in the spatial separation between ECs.