Dr. Paulo V. Santos

Paul-Drude-Insütut für Festkörperelektronik Hausvogteiplatz 5-7 10117 Berlin

Tel: (030) 203 77 22 Fax: (030) 203 77 515 Email: santos@pdi-berlin.de

Dr. Rudolf Hey

Paul-Drude-Insütut für Festkörperelektronik Hausvogteiplatz 5-7 10117 Berlin

Tel: (030) 203 77 35 Fax: (030) 20377201 Email: hey@pdi-berlin.de

Spin transport and manipulation in GaAs (110) quantum wells using surface acoustic waves

The spatial potential modulation induced by a surface acoustic wave (SAW) in semiconductor structures provides an effective way of transporting charge and spins in GaAs quantum wells. The type-II potential modulation spatially separates electrons and holes, thus extending the recombination lifetime and transporting the carriers at the SAW velocity. We have recently demonstrated that the electron-hole separation also reduces the exchange interaction between photoexcited electrons and holes, thus prolonging their spin lifetimes. [1, 2] Furthermore, the confinement by the piezoelectric field reduces spin scattering during transport, thus leading to very long (> 20 ns) spin lifetimes and transport lengths (> 100 ^m). [3, 4] This projects aims at long coherent spin transport lengths at high temperatures (up room temperatures (RT)) by combining the transport by acoustic fields with the special symmetry of GaAs (110) QWs. Emphasis will be placed on the growth of GaAs (110) structures, the generation of strong acoustic fields for efficient spin transport as well as on basic studies and control of the spin dynamics using electric, magnetic, and strain fields. The new concepts introduced here will open new perspectives for applications in spintronic devices.