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Atomic-scale fragmentation and collapse of antiferromagnetic order in a doped Mott insulator

ORAL

Abstract

Measuring magnetic and electronic properties at atomic length scales would provide crucial insight into the physics of doped antiferromagnetic Mott insulators, but this has been difficult to achieve. We use spin-polarized scanning tunneling microscopy (SP-STM) to visualize the periodic spin-resolved modulations originating from the antiferromagnetic order in a Jeff = ½ strongly spin-orbit coupled Mott insulator Sr2IrO4. We discover that near insulator-to-metal transition (IMT), the long-range antiferromagnetic order melts into a spatially fragmented state with short-range correlations. Importantly, we find that the short-range antiferromagnetic order is locally uncorrelated with the observed spectral gap magnitude. This suggests that static short-range antiferromagnetic correlations are unlikely to be the cause of the inhomogeneous closing of the spectral gap and the emergence of pseudogap regions near the IMT in doped Sr2IrO4. Our work establishes SP-STM as a powerful tool for revealing atomic-scale magnetic information in complex oxides.

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Presenters

  • He Zhao

    Boston College

Authors

  • He Zhao

    Boston College

  • Sujit Manna

    Indian Institute of Technology Delhi

  • Zach Porter

    University of California, Santa Barbara

  • Xiang Chen

    Lawrence Berkeley National Laboratory, Physics, University of California at Berkeley, University of California, Santa Barbara

  • Andrew Uzdejczyk

    Boston College

  • Jagadeesh Moodera

    Department of Physics, Massachusetts Institute of Technology, Plasma Science and Fusion Center, and Francis Bitter Magnet Laboratory, and Department of Physics, MIT, Massachusetts Institute of Technology, MASSACHUSETTS INSTITUTE OF TECHNOLOGY, Massachusetts Institute of Technology MIT

  • Ziqiang Wang

    Boston College, Department of Physics, Boston College, Physics, Boston College

  • Stephen Wilson

    University of California, Santa Barbara, Materials Department, University of California, Santa Barbara, Materials Engineering, University of California, Santa Barbara, California NanoSystems Institute/Materials, University of California, Santa Barbara

  • Ilija Zeljkovic

    Boston College