Large Negative Electronic Compressibility of LaAlO3-SrTiO3 Interfaces with Ultrathin LaAlO3 Layers

Abstract

A two-dimensional electron liquid is formed at the n-type interface between SrTiO3 and LaAlO3. Here we report on Kelvin probe microscopy measurements of the electronic compressibility of this electron system. The electronic compressibility is found to be negative for carrier densities of \approx10^13/cm^2. At even smaller densities, a metal-to-insulator transition occurs. These local measurements corroborate earlier measurements of the electronic compressibility of LaAlO3-SrTiO3 interfaces obtained by measuring the capacitance of macroscopic metal-LaAlO3-SrTiO3 capacitors.

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Cited by in corpus (12)

• Local Electrostatic Imaging of Striped Domain Order in LaAlO3/SrTiO3
• The effect of electron dielectric response on the quantum capacitance of graphene in a strong magnetic field
• Giant capacitance of a plane capacitor with a two-dimensional electron gas in a magnetic field
• Enhanced compressibility due to repulsive interaction in the Harper model
• Capacitance and compressibility of heterostructures with strong electronic correlations
• The mechanism of spin-orbit coupling in a 2D oxide interface
• Spin-orbit controlled quantum capacitance of a polar heterostructure
• Charge instabilities of the two-dimensional Hubbard model with attractive nearest neighbour interaction
• Understanding the onset of negative electronic compressibility in one- and two-band 2D electron gases: Application to LaAlO${}_3$/SrTiO${}_3$
• Anomalous Thermodynamic Properties of Electron Accumulation Layer in SrTiO${}_3$
• Novel mechanisms to enhance the capacitance beyond the classical limits in capacitors with free-electron-like electrodes
• Bad metal and negative compressibility transitions in a two-band Hubbard model