Tunable Spin and Orbital Edelstein Effect at (111) LaAlO3/SrTiO3 Interface

Nanomaterials (Basel). 2022 Jul 20;12(14):2494. doi: 10.3390/nano12142494.


Converting charge current into spin current is one of the main mechanisms exploited in spintronics. One prominent example is the Edelstein effect, namely, the generation of a magnetization in response to an external electric field, which can be realized in systems with lack of inversion symmetry. If a system has electrons with an orbital angular momentum character, an orbital magnetization can be generated by the applied electric field, giving rise to the so-called orbital Edelstein effect. Oxide heterostructures are the ideal platform for these effects due to the strong spin-orbit coupling and the lack of inversion symmetries. Beyond a gate-tunable spin Edelstein effect, we predict an orbital Edelstein effect an order of magnitude larger then the spin one at the (111) LaAlO3/SrTiO3 interface for very low and high fillings. We model the material as a bilayer of t2g orbitals using a tight-binding approach, whereas transport properties are obtained in the Boltzmann approach. We give an effective model at low filling, which explains the non-trivial behaviour of the Edelstein response, showing that the hybridization between the electronic bands crucially impacts the Edelstein susceptibility.

Keywords: Edelstein effect; orbital magnetization; orbitronics; oxide heterostructures; spin-orbit; spintronics.

Grants and funding

C.A.P. and R.C. acknowledge support from Italy’s MIUR PRIN project TOP-SPIN (Grant No. PRIN 20177SL7HC).