Orbital and spin order in oxide two-dimensional electron gases

Abstract

We describe a variational theory of multi-band two-dimensional electron gases that captures the interplay between electrostatic confining potentials, orbital-dependent interlayer electronic hopping and electron-electron interactions, and apply it to the d-band two-dimensional electron gases that form near perovskite oxide surfaces and heterojunctions. These multi-band two-dimensional electron gases are prone to the formation of Coulomb-interaction-driven orbitally-ordered nematic ground-states. We find that as the electron density is lowered and interaction effects strengthen, spontaneous orbital order occurs first, followed by spin order. We compare our results with known properties of single-component two-dimensional electron gas systems and comment on closely related physics in semiconductor quantum wells and van der Waals heterostructures.

15+1 pages, 5 figures

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Cited by in corpus (6)

• Novel metal-insulator-transition at the SrTiO3/SmTiO3 interface
• Hidden Weyl Fermions in Paramagnetic Electride Y${}_2$C
• Magnetic and nematic orders of the 2DEG at oxide (111) surfaces and interfaces
• Signatures of Electronic Nematicity in (111) LaAlO${}_3$/SrTiO${}_3$ Interfaces
• Anisotropic Magnetoresistance in Multiband Systems: 2DEGs and Polar Metals at Oxide Interfaces
• Majorana zero modes in a quantum wire platform without Rashba spin-orbit coupling