Electronic and magnetic state of LaMnO3 epitaxially strained on SrTiO3: Effect of local correlation and nonlocal exchange

Hrishit Banerjee, Oleg Janson, Karsten Held, and Tanusri Saha-Dasgupta
Phys. Rev. B 100, 115143 – Published 18 September 2019

Abstract

Motivated by the puzzling report of the observation of a ferromagnetic insulating state in LaMnO3/SrTiO3 heterostructures, we calculate the electronic and magnetic state of LaMnO3, coherently matched to a SrTiO3 square substrate within a “strained-bulk” geometry. We employ three different density functional theory based computational approaches: (a) density functional theory (DFT) supplemented with Hubbard U(DFT+U), (b) DFT + dynamical mean-field theory (DMFT), and (c) a hybrid functional treatment of the exchange-correlation functional. While the first two approaches include local correlations and exchange at Mn sites, treated in a static and dynamic manner, respectively, the last one takes into account the effect of nonlocal exchange at all sites. We find in all three approaches that the compressive strain induced by the square substrate of SrTiO3 turns LaMnO3, from an antiferromagnet with sizable orbital polarization, to a ferromagnet with suppressed Jahn-Teller distortion, in agreement with experiment. However, while both DFT+U and DFT+DMFT provide a metallic solution, only the hybrid calculations result in an insulating solution, as observed in experiment. This insulating behavior is found to originate from an electronic charge disproportionation. Our conclusions remain valid when we investigate LaMnO3/SrTiO3 within the experimental setup of a superlattice geometry using DFT+U and hybrid calculations.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Received 27 July 2019

DOI:https://doi.org/10.1103/PhysRevB.100.115143

©2019 American Physical Society

Physics Subject Headings (PhySH)

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Hrishit Banerjee1, Oleg Janson2,3, Karsten Held3, and Tanusri Saha-Dasgupta4,5,*

  • 1Insitut für Theoretische Physik–Computational Physics, TU Graz, Petersgaße 16, Graz 8010, Austria
  • 2Institute for Theoretical Solid State Physics, IFW Dresden, Helmholtzstraße 20, 01069 Dresden, Germany
  • 3Institut für Festkörperphysik, TU Wien, Wiedner Hauptstraße 8-10, Vienna, Austria
  • 4S. N. Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake, Kolkata, West Bengal 700106, India
  • 5Indian Association for the Cultivation of Science, 2A & 2B, Raja Subodh Chandra Mallick Rd., Jadavpur, Kolkata, West Bengal 700032, India

  • *t.sahadasgupta@gmail.com

Article Text (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 100, Iss. 11 — 15 September 2019

Reuse & Permissions
Access Options
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review B

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×