Nanoscale Femtosecond Dynamics of Mott Insulator (Ca0.99Sr0.01)2RuO4

Rocco A. Vitalone; Aaron J. Sternbach; Benjamin A. Foutty; Alexander S. McLeod; Chanchal Sow; Denis Golez; Fumihiko Nakamura; Yoshiteru Maeno; Abhay N. Pasupathy; Antoine Georges; Andrew J. Millis; D. N. Basov

doi:10.1021/acs.nanolett.2c00581

Nanoscale Femtosecond Dynamics of Mott Insulator (Ca_0.99Sr_0.01)₂RuO₄

Rocco A. Vitalone, Aaron J. Sternbach, Benjamin A. Foutty, Alexander S. McLeod, Chanchal Sow, Denis Golez, Fumihiko Nakamura, Yoshiteru Maeno, Abhay N. Pasupathy, Antoine Georges, Andrew J. Millis, D. N. Basov

Physics and Astronomy (Twin Cities)

Research output: Contribution to journal › Article › peer-review

5 Scopus citations

Abstract

Ca2RuO4 is a transition-metal oxide that exhibits a Mott insulator-metal transition (IMT) concurrent with a symmetry-preserving Jahn-Teller distortion (JT) at 350 K. The coincidence of these two transitions demonstrates a high level of coupling between the electronic and structural degrees of freedom in Ca2RuO4. Using spectroscopic measurements with nanoscale spatial resolution, we interrogate the interplay of the JT and IMT through the temperature-driven transition. Then, we introduce photoexcitation with subpicosecond temporal resolution to explore the coupling of the JT and IMT via electron-hole injection under ambient conditions. Through the temperature-driven IMT, we observe phase coexistence in the form of a stripe phase existing at the domain wall between macroscopic insulating and metallic domains. Through ultrafast carrier injection, we observe the formation of midgap states via enhanced optical absorption. We propose that these midgap states become trapped by lattice polarons originating from the local perturbation of the JT.

Original language	English (US)
Pages (from-to)	5689-5697
Number of pages	9
Journal	Nano letters
Volume	22
Issue number	14
DOIs	https://doi.org/10.1021/acs.nanolett.2c00581
State	Published - Jul 27 2022

Bibliographical note

Funding Information:
Research at Columbia is supported by the Center on Precision-Assembled Quantum Materials, funded through the U.S. National Science Foundation (NSF) Materials Research Science and Engineering Centers (award no. DMR-2011738). D.N.B. is the Moore Investigator in Quantum Materials EPIQS GBMF9455 and is also the Vannevar Bush Faculty Fellow ONR-VB: N00014-19-1-2630. F.N. and Y.M. are supported by the JSPS KAKENHI (grant no. JP17H06136). Y.M. is supported by the JSPS Core-to-Core Program. D.G. is supported by the Slovenian Research Agency (ARRS) under programs J1-2455 and P1-0044. The Flatiron Institute is a division of the Simons Foundation.

Publisher Copyright:
© 2022 American Chemical Society.

Keywords

CaRuO, correlated Mott insulator
insulator-metal transition
midgap states
transient scanning near-field optical microscopy (Tr-SNOM)
ultrafast pump-probe

PubMed: MeSH publication types

Journal Article

Access

10.1021/acs.nanolett.2c00581

OpenUrl availability

Full text

Cite this

@article{a8dadb5afa5d49fe8fa4a01ebadc17aa,

title = "Nanoscale Femtosecond Dynamics of Mott Insulator (Ca0.99Sr0.01)2RuO4",

abstract = "Ca2RuO4 is a transition-metal oxide that exhibits a Mott insulator-metal transition (IMT) concurrent with a symmetry-preserving Jahn-Teller distortion (JT) at 350 K. The coincidence of these two transitions demonstrates a high level of coupling between the electronic and structural degrees of freedom in Ca2RuO4. Using spectroscopic measurements with nanoscale spatial resolution, we interrogate the interplay of the JT and IMT through the temperature-driven transition. Then, we introduce photoexcitation with subpicosecond temporal resolution to explore the coupling of the JT and IMT via electron-hole injection under ambient conditions. Through the temperature-driven IMT, we observe phase coexistence in the form of a stripe phase existing at the domain wall between macroscopic insulating and metallic domains. Through ultrafast carrier injection, we observe the formation of midgap states via enhanced optical absorption. We propose that these midgap states become trapped by lattice polarons originating from the local perturbation of the JT.",

keywords = "CaRuO, correlated Mott insulator, insulator-metal transition, midgap states, transient scanning near-field optical microscopy (Tr-SNOM), ultrafast pump-probe",

author = "Vitalone, {Rocco A.} and Sternbach, {Aaron J.} and Foutty, {Benjamin A.} and McLeod, {Alexander S.} and Chanchal Sow and Denis Golez and Fumihiko Nakamura and Yoshiteru Maeno and Pasupathy, {Abhay N.} and Antoine Georges and Millis, {Andrew J.} and Basov, {D. N.}",

note = "Funding Information: Research at Columbia is supported by the Center on Precision-Assembled Quantum Materials, funded through the U.S. National Science Foundation (NSF) Materials Research Science and Engineering Centers (award no. DMR-2011738). D.N.B. is the Moore Investigator in Quantum Materials EPIQS GBMF9455 and is also the Vannevar Bush Faculty Fellow ONR-VB: N00014-19-1-2630. F.N. and Y.M. are supported by the JSPS KAKENHI (grant no. JP17H06136). Y.M. is supported by the JSPS Core-to-Core Program. D.G. is supported by the Slovenian Research Agency (ARRS) under programs J1-2455 and P1-0044. The Flatiron Institute is a division of the Simons Foundation. Publisher Copyright: {\textcopyright} 2022 American Chemical Society.",

year = "2022",

month = jul,

day = "27",

doi = "10.1021/acs.nanolett.2c00581",

language = "English (US)",

volume = "22",

pages = "5689--5697",

journal = "Nano letters",

issn = "1530-6984",

publisher = "American Chemical Society",

number = "14",

}

TY - JOUR

T1 - Nanoscale Femtosecond Dynamics of Mott Insulator (Ca0.99Sr0.01)2RuO4

AU - Vitalone, Rocco A.

AU - Sternbach, Aaron J.

AU - Foutty, Benjamin A.

AU - McLeod, Alexander S.

AU - Sow, Chanchal

AU - Golez, Denis

AU - Nakamura, Fumihiko

AU - Maeno, Yoshiteru

AU - Pasupathy, Abhay N.

AU - Georges, Antoine

AU - Millis, Andrew J.

AU - Basov, D. N.

N1 - Funding Information: Research at Columbia is supported by the Center on Precision-Assembled Quantum Materials, funded through the U.S. National Science Foundation (NSF) Materials Research Science and Engineering Centers (award no. DMR-2011738). D.N.B. is the Moore Investigator in Quantum Materials EPIQS GBMF9455 and is also the Vannevar Bush Faculty Fellow ONR-VB: N00014-19-1-2630. F.N. and Y.M. are supported by the JSPS KAKENHI (grant no. JP17H06136). Y.M. is supported by the JSPS Core-to-Core Program. D.G. is supported by the Slovenian Research Agency (ARRS) under programs J1-2455 and P1-0044. The Flatiron Institute is a division of the Simons Foundation. Publisher Copyright: © 2022 American Chemical Society.

PY - 2022/7/27

Y1 - 2022/7/27

N2 - Ca2RuO4 is a transition-metal oxide that exhibits a Mott insulator-metal transition (IMT) concurrent with a symmetry-preserving Jahn-Teller distortion (JT) at 350 K. The coincidence of these two transitions demonstrates a high level of coupling between the electronic and structural degrees of freedom in Ca2RuO4. Using spectroscopic measurements with nanoscale spatial resolution, we interrogate the interplay of the JT and IMT through the temperature-driven transition. Then, we introduce photoexcitation with subpicosecond temporal resolution to explore the coupling of the JT and IMT via electron-hole injection under ambient conditions. Through the temperature-driven IMT, we observe phase coexistence in the form of a stripe phase existing at the domain wall between macroscopic insulating and metallic domains. Through ultrafast carrier injection, we observe the formation of midgap states via enhanced optical absorption. We propose that these midgap states become trapped by lattice polarons originating from the local perturbation of the JT.

AB - Ca2RuO4 is a transition-metal oxide that exhibits a Mott insulator-metal transition (IMT) concurrent with a symmetry-preserving Jahn-Teller distortion (JT) at 350 K. The coincidence of these two transitions demonstrates a high level of coupling between the electronic and structural degrees of freedom in Ca2RuO4. Using spectroscopic measurements with nanoscale spatial resolution, we interrogate the interplay of the JT and IMT through the temperature-driven transition. Then, we introduce photoexcitation with subpicosecond temporal resolution to explore the coupling of the JT and IMT via electron-hole injection under ambient conditions. Through the temperature-driven IMT, we observe phase coexistence in the form of a stripe phase existing at the domain wall between macroscopic insulating and metallic domains. Through ultrafast carrier injection, we observe the formation of midgap states via enhanced optical absorption. We propose that these midgap states become trapped by lattice polarons originating from the local perturbation of the JT.

KW - CaRuO, correlated Mott insulator

KW - insulator-metal transition

KW - midgap states

KW - transient scanning near-field optical microscopy (Tr-SNOM)

KW - ultrafast pump-probe

UR - http://www.scopus.com/inward/record.url?scp=85135370825&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85135370825&partnerID=8YFLogxK

U2 - 10.1021/acs.nanolett.2c00581

DO - 10.1021/acs.nanolett.2c00581

M3 - Article

C2 - 35839312

AN - SCOPUS:85135370825

SN - 1530-6984

VL - 22

SP - 5689

EP - 5697

JO - Nano letters

JF - Nano letters

IS - 14

ER -