Hydrostatic pressure response of an oxide two-dimensional electron system

Abstract

Two-dimensional electron systems with fascinating properties exist in multilayers of standard semiconductors, on helium surfaces, and in oxides. Compared to the two-dimensional (2D) electron gases of semiconductors, the 2D electron systems in oxides are typically more strongly correlated and more sensitive to the microscopic structure of the hosting lattice. This sensitivity suggests that the oxide 2D systems are highly tunable by hydrostatic pressure. Here we explore the effects of hydrostatic pressure on the well-characterized 2D electron system formed at LaAlO${}_3$ -SrTiO${}_3$ interfaces[1] and measure a pronounced, unexpected response. Pressure of $\sim$2 GPa reversibly doubles the 2D carrier density $n_s$ at 4 K. Along with the increase of $n_s$, the conductivity and mobility are reduced under pressure. First-principles pressure simulations reveal the same behavior of the carrier density and suggest a possible mechanism of the mobility reduction, based on the dielectric properties of both materials and their variation under external pressure.

arXiv comment13 pages and 10 figures main text. 6 pages and 10 figures supplementary information. Phys Rev B (in press)

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Cited by in corpus (6)

• Inter-orbital topological superconductivity in spin-orbit coupled superconductors with inversion symmetry breaking
• Band-Order Anomaly at the γ-Al2O3/SrTiO3 Interface Drives the Electron-Mobility Boost
• Electronic properties of LaAlO3/SrTiO3 n-type interfaces: A GGA+U study
• Oxygen vacancies and hydrogen doping in LaAlO3/SrTiO3 heterostructures: electronic properties and impact on surface and interface reconstruction
• The mechanism of spin-orbit coupling in a 2D oxide interface
• Coexistence of high electron-mobility, unpaired spins, and superconductivity at high carrier density SrTiO${}_3$-based interfaces