Charge order textures induced by non-linear couplings in a half-doped manganite

Ismail El Baggari; David J Baek; Michael J Zachman; Di Lu; Yasuyuki Hikita; Harold Y Hwang; Elizabeth A Nowadnick; Lena F Kourkoutis

doi:10.1038/s41467-021-24026-7

Charge order textures induced by non-linear couplings in a half-doped manganite

Nat Commun. 2021 Jun 18;12(1):3747. doi: 10.1038/s41467-021-24026-7.

Authors

Ismail El Baggari^#¹, David J Baek^#^{2

3}, Michael J Zachman^{4

5}, Di Lu^{6

7

8}, Yasuyuki Hikita^{7

9}, Harold Y Hwang^{7

9}, Elizabeth A Nowadnick¹⁰, Lena F Kourkoutis^{11

12}

Affiliations

¹ Department of Physics, Cornell University, Ithaca, NY, USA.
² School of Electrical and Computer Engineering, Cornell University, Ithaca, NY, USA.
³ Intel Corp., Hillsboro, OR, USA.
⁴ School of Applied and Engineering Physics, Cornell University, Ithaca, NY, USA.
⁵ Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA.
⁶ Department of Physics, Stanford University, Stanford, CA, USA.
⁷ Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA, USA.
⁸ Materials Science and Engineering, Northwestern University, Evanston, IL, USA.
⁹ Department of Applied Physics, Stanford University, Stanford, CA, USA.
¹⁰ Department of Materials Science and Engineering, University of California Merced, Merced, CA, USA.
¹¹ School of Applied and Engineering Physics, Cornell University, Ithaca, NY, USA. lena.f.kourkoutis@cornell.edu.
¹² Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, NY, USA. lena.f.kourkoutis@cornell.edu.

^# Contributed equally.

Abstract

The self-organization of strongly interacting electrons into superlattice structures underlies the properties of many quantum materials. How these electrons arrange within the superlattice dictates what symmetries are broken and what ground states are stabilized. Here we show that cryogenic scanning transmission electron microscopy (cryo-STEM) enables direct mapping of local symmetries and order at the intra-unit-cell level in the model charge-ordered system Nd_1/2Sr_1/2MnO₃. In addition to imaging the prototypical site-centered charge order, we discover the nanoscale coexistence of an exotic intermediate state which mixes site and bond order and breaks inversion symmetry. We further show that nonlinear coupling of distinct lattice modes controls the selection between competing ground states. The results demonstrate the importance of lattice coupling for understanding and manipulating the character of electronic self-organization and that cryo-STEM can reveal local order in strongly correlated systems at the atomic scale.

Abstract

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