Local Density of States Study of a Spin-Orbit-Coupling Induced Mott Insulator Sr₂IrO₄

Authors

Jixia Dai, University of Colorado - Boulder
Eduardo Calleja, University of Colorado - Boulder
Gang Cao, University of KentuckyFollow
Kyle McElroy, University of Colorado - Boulder

Abstract

We present scanning tunneling microscopy and spectroscopy experiments on the novel J_eff=1/2 Mott insulator Sr₂IrO₄. Local density of states (LDOS) measurements show an intrinsic insulating gap of 620 meV that is asymmetric about the Fermi level and is larger than previously reported values. The size of this gap suggests that Sr₂IrO₄ is likely a Mott rather than Slater insulator. In addition, we found a small number of native defects which create in-gap spectral weight. Atomically resolved LDOS measurements on and off the defects show that this energy gap is quite fragile. Together the extended nature of the 5d electrons and poor screening of defects help explain the elusive nature of this gap.

Document Type

Article

Publication Date

7-9-2014

Notes/Citation Information

Published in Physical Review B: Condensed Matter and Materials Physics, v. 90, no. 4, article 041102, p. 1-5.

©2014 American Physical Society

The copyright holder has granted permission for posting the article here.

Digital Object Identifier (DOI)

http://dx.doi.org/10.1103/PhysRevB.90.041102

Funding Information

G.C. acknowledges support by NSF through Grants No. DMR-0856234 and No. EPS-0814194. K.M. acknowledges support by Alfred P. Sloan Foundation.

Repository Citation

Dai, Jixia; Calleja, Eduardo; Cao, Gang; and McElroy, Kyle, "Local Density of States Study of a Spin-Orbit-Coupling Induced Mott Insulator Sr₂IrO₄" (2014). Physics and Astronomy Faculty Publications. 292.
https://uknowledge.uky.edu/physastron_facpub/292