Upper Limit to Magnetism in ${\mathrm{LaAlO}}_{3}/{\mathrm{SrTiO}}_{3}$ Heterostructures

Upper Limit to Magnetism in ${LaAlO}_{3} / {SrTiO}_{3}$ Heterostructures

M. R. Fitzsimmons, N. W. Hengartner, S. Singh, M. Zhernenkov, F. Y. Bruno, J. Santamaria, A. Brinkman, M. Huijben, H. J. A. Molegraaf, J. de la Venta, and Ivan K. Schuller

Phys. Rev. Lett. 107, 217201 – Published 14 November 2011

Abstract

Using polarized neutron reflectometry we measured the neutron spin-dependent reflectivity from four ${LaAlO}_{3} / {SrTiO}_{3}$ superlattices. Our results imply that the upper limit for the magnetization averaged over the lateral dimensions of the sample induced by an 11 T magnetic field at 1.7 K is less than 2 G. SQUID magnetometry of the neutron superlattice samples sporadically finds an enhanced moment, possibly due to experimental artifacts. These observations set important restrictions on theories which imply a strongly enhanced magnetism at the interface between ${LaAlO}_{3}$ and ${SrTiO}_{3}$ .

Received 2 August 2011

DOI:https://doi.org/10.1103/PhysRevLett.107.217201

Authors & Affiliations

M. R. Fitzsimmons¹, N. W. Hengartner¹, S. Singh^1,2, M. Zhernenkov¹, F. Y. Bruno³, J. Santamaria³, A. Brinkman⁴, M. Huijben⁴, H. J. A. Molegraaf⁴, J. de la Venta⁵, and Ivan K. Schuller⁵

¹Los Alamos National Laboratory, Los Alamos New Mexico 87545 USA
²Solid State Physics Division, Bhabha Atomic Research Center, Mumbai- 400085, India
³GFMC. Dpto. Fisica Aplicada III, Universidad Complutense de Madrid, 28040 Madrid. Spain
⁴MESA+ Institute for Nanotechnology, University of Twente, Enschede, The Netherlands
⁵Department of Physics and Center for Advanced Nanoscience, University of California San Diego, La Jolla, California 92093 USA