Despite many efforts to rationalize the strongly correlated electronic ground states in doped Mott insulators, the nature of the doping-induced insulator-to-metal transition is still a subject under intensive investigation. Here, we probe the nanoscale electronic structure of the Mott insulator Sr2IrO4−δ with low-temperature scanning tunneling microscopy and find an enhanced local density of states (LDOS) inside the Mott gap at the location of individual defects which we interpret as defects at apical oxygen sites. A chiral behavior in the topography for those defects has been observed. We also visualize the local enhanced conductance arising from the overlapping of defect states which induces finite LDOS inside of the Mott gap. By combining these findings with the typical spatial extension of isolated defects of about 2 nm, our results indicate that the insulator-to-metal transition in Sr2IrO4−δ could be percolative in nature.
Description
Phys. Rev. Research 3, 023075 (2021) - Evidence for a percolative Mott insulator-metal transition in doped ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$
%0 Journal Article
%1 PhysRevResearch.3.023075
%A Sun, Zhixiang
%A Guevara, Jose M.
%A Sykora, Steffen
%A Pärschke, Ekaterina M.
%A Manna, Kaustuv
%A Maljuk, Andrey
%A Wurmehl, Sabine
%A van den Brink, Jeroen
%A Büchner, Bernd
%A Hess, Christian
%D 2021
%I American Physical Society
%J Phys. Rev. Res.
%K a b
%N 2
%P 023075
%R 10.1103/PhysRevResearch.3.023075
%T Evidence for a percolative Mott insulator-metal transition in doped Sr$_2$IrO$_4$
%U https://link.aps.org/doi/10.1103/PhysRevResearch.3.023075
%V 3
%X Despite many efforts to rationalize the strongly correlated electronic ground states in doped Mott insulators, the nature of the doping-induced insulator-to-metal transition is still a subject under intensive investigation. Here, we probe the nanoscale electronic structure of the Mott insulator Sr2IrO4−δ with low-temperature scanning tunneling microscopy and find an enhanced local density of states (LDOS) inside the Mott gap at the location of individual defects which we interpret as defects at apical oxygen sites. A chiral behavior in the topography for those defects has been observed. We also visualize the local enhanced conductance arising from the overlapping of defect states which induces finite LDOS inside of the Mott gap. By combining these findings with the typical spatial extension of isolated defects of about 2 nm, our results indicate that the insulator-to-metal transition in Sr2IrO4−δ could be percolative in nature.
@article{PhysRevResearch.3.023075,
abstract = {Despite many efforts to rationalize the strongly correlated electronic ground states in doped Mott insulators, the nature of the doping-induced insulator-to-metal transition is still a subject under intensive investigation. Here, we probe the nanoscale electronic structure of the Mott insulator Sr2IrO4−δ with low-temperature scanning tunneling microscopy and find an enhanced local density of states (LDOS) inside the Mott gap at the location of individual defects which we interpret as defects at apical oxygen sites. A chiral behavior in the topography for those defects has been observed. We also visualize the local enhanced conductance arising from the overlapping of defect states which induces finite LDOS inside of the Mott gap. By combining these findings with the typical spatial extension of isolated defects of about 2 nm, our results indicate that the insulator-to-metal transition in Sr2IrO4−δ could be percolative in nature.},
added-at = {2023-07-03T11:16:20.000+0200},
author = {Sun, Zhixiang and Guevara, Jose M. and Sykora, Steffen and Pärschke, Ekaterina M. and Manna, Kaustuv and Maljuk, Andrey and Wurmehl, Sabine and van den Brink, Jeroen and Büchner, Bernd and Hess, Christian},
biburl = {https://www.bibsonomy.org/bibtex/2f4878cd863f591d902fa62f049824e65/ctqmat},
day = 27,
description = {Phys. Rev. Research 3, 023075 (2021) - Evidence for a percolative Mott insulator-metal transition in doped ${\mathrm{Sr}}_{2}{\mathrm{IrO}}_{4}$},
doi = {10.1103/PhysRevResearch.3.023075},
interhash = {1e89251d86b62cec6aeca80bc04e62d9},
intrahash = {f4878cd863f591d902fa62f049824e65},
journal = {Phys. Rev. Res.},
keywords = {a b},
month = {04},
number = 2,
numpages = {9},
pages = 023075,
publisher = {American Physical Society},
timestamp = {2023-10-19T10:15:36.000+0200},
title = {Evidence for a percolative Mott insulator-metal transition in doped Sr$_{\mathbf{2}}$IrO$_{\mathbf{4}}$},
url = {https://link.aps.org/doi/10.1103/PhysRevResearch.3.023075},
volume = 3,
year = 2021
}