Electric-field-induced pyroelectric order and localization of the confined electrons in LaAlO3/SrTiO3 heterostructures

Bibliographic Details
Title: Electric-field-induced pyroelectric order and localization of the confined electrons in LaAlO3/SrTiO3 heterostructures
Authors: Rössle, M., Kim, K. W., Dubroka, A., Marsik, P., Wang, C. N., Jany, R., Richter, C., Mannhart, J., Schneider, C. W., Frano, A., Wochner, P., Lu, Y., Keimer, B., Shukla, D. K., Strempfer, J., Bernhard, C.
Source: Phys. Rev. Lett. 110, 136805 (2013)
Publication Year: 2012
Collection: Condensed Matter
Subject Terms: Condensed Matter - Materials Science, Condensed Matter - Strongly Correlated Electrons, Condensed Matter - Superconductivity
More Details: With infrared ellipsometry, x-ray diffraction, and electric transport measurements we investigated the electric-field-effect on the confined electrons at the LaAlO3/SrTiO3 interface. We obtained evidence that the localization of the electrons at low temperature and negative gate voltage is induced, or at least strongly enhanced, by a pyroelectric phase transition in SrTiO3 which strongly reduces the lattice polarizability and the subsequent Coulomb screening. In particular, we show that the charge localisation and the polar order of SrTiO3 both develop below about 50 K and exhibit similar, unipolar hysteresis loops as a function of the gate voltage. Our findings suggest that the pyroelectric order also plays an important role in the quantum phase transition at very low temperatures where superconductivity is suppressed by an electric field.
Comment: 5 pages, 4 figures, supplementary material
Document Type: Working Paper
DOI: 10.1103/PhysRevLett.110.136805
Access URL: http://arxiv.org/abs/1209.4739
Accession Number: edsarx.1209.4739
Database: arXiv
More Details
DOI:10.1103/PhysRevLett.110.136805