Generation and Detection of Spin Currents in Semiconductor Nanostructures with Strong Spin-Orbit Interaction

Fabrizio Nichele, Szymon Hennel, Patrick Pietsch, Werner Wegscheider, Peter Stano, Philippe Jacquod, Thomas Ihn, Klaus Ensslin

Published 2014-09-14Version 1

Storing, transporting and manipulating information using the electron spin resides at the heart of spintronics. Fundamental for future spintronic applications is the possibility to control spin currents in solid state systems. Among the different approaches, the use of semiconductors with strong spin-orbit interaction promises fast and scalable spin control with all-electrical methods. Here we establish both the generation and measurement of pure spin currents (i.e. not accompanied by charge flow) in multi-terminal semiconductor nanostructures. The generation of spin currents is purely electrical and mediated by the spin dynamics in systems with strong SOI. The measurement is accomplished using a spin-to-charge conversion technique, based on the magnetic field symmetry of easily measurable electrical quantities. Calibrating the spin-to-charge conversion via the conductance of a quantum point contact, we quantitatively measure the mesoscopic spin Hall effect in a multi-terminal GaAs dot. We report spin currents up to 174 pA, corresponding to 4% charge-to-spin conversion efficiency.