Weak antilocalization of high mobility holes in a strained Germanium quantum well heterostructure

We present the observation of weak antilocalization due to the Rashba spin-orbit interaction, through magnetoresistance measurements performed at low temperatures and low magnetic fields on a high mobility (777 000cm²V^-1s^-1) p-Ge/SiGe quantum well heterostructure. The measured magnetoresistance over a temperature range of 0.44 to 11.2K shows an apparent transition from weak localization to weak antilocalization. The temperature dependence of the zero field conductance correction is indicative of weak localization using the simplest model, despite the clear existence of weak antilocalization. The Rashba interaction present in this material, and the absence of the un-tuneable Dresselhaus interaction, indicates that Ge quantum well heterostructures are highly suitable for semiconductor spintronic applications, particularly the proposed spin field effect transistor.