Quasiparticle interference and quantum confinement in a correlated Rashba spin-split 2D electron liquid

Exploiting inversion symmetry breaking (ISB) in systems with strong spin-orbit coupling promises control of spin through electric fields-crucial to achieve miniaturization in spintronic devices. Delivering on this promise requires a two-dimensional electron gas with a spin precession length shorter than the spin coherence length and a large spin splitting so that spin manipulation can be achieved over length scales of nanometers. Recently, the transition metal oxide terminations of delafossite oxides were found to exhibit a large Rashba spin splitting dominated by ISB. In this limit, the Fermi surface exhibits the same spin texture as for weak ISB, but the orbital texture is completely different, raising questions about the effect on quasiparticle scattering. We demonstrate that the spin-orbital selection rules relevant for conventional Rashba system are obeyed as true spin selection rules in this correlated electron liquid and determine its spin coherence length from quasiparticle interference imaging.

Automated summary

Exploiting inversion symmetry breaking in systems with strong spin-orbit coupling allows for spin control through electric fields, requiring specific conditions for a two-dimensional electron gas. Recent studies have shown a large Rashba spin splitting on the transition metal oxide terminations, indicating a different orbital effect that raises questions about quasiparticle scattering. The spin-orbital selection rules relevant for conventional Rashba systems are demonstrated to be true spin selection rules in this correlated electron liquid, with the spin coherence length determined through quasiparticle interference imaging.