Electronic Phases and Phase Separation in the Hubbard-Holstein Model of a Polar Interface

Abstract

From a mean-field solution of the Hubbard-Holstein model, we show that a rich variety of different electronic phases can result at the interface between two polar materials such as LaAlO${}_3$/SrTiO${}_3$. Depending on the strengths of the various competing interactions, viz., the electronic kinetic energy, electron-phonon interaction, Coulomb energy, and electronic screening strength, the electrons could (i) either be strongly confined to the interface forming a 2D metallic or an insulating phase, (ii) spread deeper into the bulk making a 3D phase, or (iii) become localized at individual sites forming a Jahn-Teller polaronic phase. In the polaronic phase, the Coulomb interaction could lead to unpaired electrons resulting in magnetic Kondo centers. Under appropriate conditions, electronic phase separation may also occur resulting in the coexistence of metallic and insulating regions at the interface.

7 pages, 10 figures

References in corpus (12)

• Magnetic effects at the interface between nonmagnetic oxides
• Electric Field Control of the LaAlO${}_3$/SrTiO${}_3$ Interface Ground State
• Origin of charge density at LaAlO3-on-SrTiO3 hetero-interfaces; possibility of intrinsic doping
• Avoiding the polarization catastrophe in LaAlO3 overlayers on SrTiO3(001) through a polar distortion
• Microwave imaging of mesoscopic percolating network in a manganite thin film
• Towards two-dimensional metallic behavior at LaAlO3/SrTiO3 interfaces
• Parallel electron-hole bilayer conductivity from electronic interface reconstruction
• Electronic structure induced reconstruction and magnetic ordering at the LaAlO${}_3|$SrTiO${}_3$ interface
• Oxide superlattices with alternating p and n interfaces
• Fundamental asymmetry in interfacial electronic reconstruction between insulating oxides
• Phase diagram for Coulomb-frustrated phase separation in systems with negative short-range compressibility
• Charge ordering and magnetism in quarter-filled Hubbard-Holstein model

Cited by in corpus (7)

• Electrolyte gate-controlled Kondo effect in SrTiO3
• Ferromagnetic exchange, spin-orbit coupling and spiral magnetism at the LaAlO_3/SrTiO_3 interface
• Emerging magnetism and electronic phase separation at titanate interfaces
• Enhanced spin-orbit interaction and Kondo scattering in $\delta$-doped LaTiO${}_3$/SrTiO${}_3$ interfaces
• Electronic phase separation at LaAlO3/SrTiO3 interfaces tunable by oxygen deficiency
• Electronic and magnetic properties in strongly correlated heterostructures
• Kondo effect with tunable spin orbit interaction in LaTiO3/CeTiO3/SrTiO3 heterostructure