Dimensionality-Induced Change in Topological Order in Multiferroic Oxide Superlattices

Megan E Holtz; Elliot S Padgett; Rachel Steinhardt; Charles M Brooks; Dennis Meier; Darrell G Schlom; David A Muller; Julia A Mundy

doi:10.1103/PhysRevLett.126.157601

Dimensionality-Induced Change in Topological Order in Multiferroic Oxide Superlattices

Phys Rev Lett. 2021 Apr 16;126(15):157601. doi: 10.1103/PhysRevLett.126.157601.

Authors

Megan E Holtz^{1

2}, Elliot S Padgett¹, Rachel Steinhardt², Charles M Brooks², Dennis Meier³, Darrell G Schlom^{2

4

5}, David A Muller^{1

4}, Julia A Mundy^{1

6}

Affiliations

¹ School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA.
² Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, USA.
³ Department of Materials Science and Engineering, Norwegian University of Science and Technology, NTNU, 7491 Trondheim, Norway.
⁴ Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853, USA.
⁵ Leibniz-Institut für Kristallzüchtung, Max-Born-Straβe 2, 12489 Berlin, Germany.
⁶ Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.

PMID: 33929216
DOI: 10.1103/PhysRevLett.126.157601

Abstract

We construct ferroelectric (LuFeO_{3})_{m}/(LuFe_{2}O_{4}) superlattices with varying index m to study the effect of confinement on topological defects. We observe a thickness-dependent transition from neutral to charged domain walls and the emergence of fractional vortices. In thin LuFeO_{3} layers, the volume fraction of domain walls grows, lowering the symmetry from P6_{3}cm to P3c1 before reaching the nonpolar P6_{3}/mmc state, analogous to the group-subgroup sequence observed at the high-temperature ferroelectric to paraelectric transition. Our study shows how dimensional confinement stabilizes textures beyond those in bulk ferroelectric systems.