[15a-PB5-1~4] 13.6 Semiconductor English Session

▼ [15a-PB5-1] Thermally Efficient Electron Spin Injection in InGaAs Quantum Well and Quantum Dot Tunnel-Coupled Nanostructures

〇Shula Chen¹, Takayuki Kiba², Junichi Takayama¹, Akihiro Murayama¹ (1.Hokkaido Univ., 2.Kitami Inst. of Tech.)

キーワード：quantum well and quantum dot,spin,time resolved photoluminescence

Time-resolved optical spin orientation spectroscopy was employed to investigate electron spin injection in InGaAs quantum well (QW) and quantum dot (QD) tunnel-coupled nanostructures. At 6K, both QW ground state (GS) and higher-lying QD excited state (ES) show large photoluminescence circular polarization up to 50%, indicating efficient spin transfer from QW to QD. With increasing temperature (T), the injected initial electron spin polarizatin undergoes only slight change, exhibiting weak T-dependence. This behavior is explained as due to T-accelerated phonon scattering which fast transfers electron spin from QW GS to QD ES before they are randomized in QW. Such quantum-coupled structure is promising for application as spin injector in spin-based devices.