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 LaAlO3 -SrTiO3 interfaces[1] and measure a pronounced, unexpected response. Pressure of ∼2 GPa reversibly doubles the 2D carrier density ns at 4 K. Along with the increase of ns, 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.
@article{arxiv.1605.08528,
title = {Hydrostatic pressure response of an oxide two-dimensional electron system},
author = {J. Zabaleta and V. S. Borisov and R. Wanke and H. O. Jeschke and S. C. Parks and B. Baum and A. Teker and T. Harada and K. Syassen and T. Kopp and N. Pavlenko and R. Valentí and J. Mannhart},
journal= {arXiv preprint arXiv:1605.08528},
year = {2016}
}
Comments
13 pages and 10 figures main text. 6 pages and 10 figures supplementary information. Phys Rev B (in press)