Journal Club do Departamento de Física dos Materiais e Mecânica
Nesta semana o pós-graduando Flávio Campopiano Dias de Moraes, do Laboratório de Novos Materiais
Semicondutores, apresentará o artigo:
"Long-range and high-speed electronic spin-transport at a GaAs/AlGaAs semiconductor interface"
L. Nádvorník et al.
Data: 31 de maio de 2016 (terça-feira)
Horário: às 12h10min
Local: Sala de Seminários José Roberto Leite - Ed. Alessandro Volta (bloco C) - sala 110
Abstract:
Spin-valves or spin-transistors in magnetic memories and logic elements are examples of structures whose functionality depends crucially on the length and time-scales at which spin-information is transferred through the device. In our work we employ spatially resolved optical pump-and-probe technique to investigate these fundamental spin-transport parameters in a model semiconductor system. We demonstrate that in an undoped GaAs/AlGaAs layer, spins are detected at distances reaching more than ten microns at times as short as nanoseconds. We have achieved this unprecedented combination of long-range and high-speed electronic spin-transport by simultaneously suppressing mechanisms that limit the spin life-time and the mobility of carriers. By exploring a series of structures we demonstrate that the GaAs/AlGaAs interface can provide superior spin-transport characteristics whether deposited directly on the substrate or embedded in complex semiconductor heterostructures. We confi!
rm our conclusions by complementing the optical experiments with dc and terahertz photo-conductivity measurements.
http://www.nature.com/articles/srep22901
