Hallmarks of Hunds coupling in the Mott insulator Ca 2 RuO 4

D. Sutter; C. G. Fatuzzo; S. Moser; M. Kim; R. Fittipaldi; A. Vecchione; V. Granata; Y. Sassa; F. Cossalter; G. Gatti; M. Grioni; H. M. Rønnow; N. C. Plumb; C. E. Matt; M. Shi; M. Hoesch; T. K. Kim; T. R. Chang; H. T. Jeng; C. Jozwiak; A. Bostwick; E. Rotenberg; A. Georges; T. Neupert; J. Chang

doi:10.1038/ncomms15176

Hallmarks of Hunds coupling in the Mott insulator Ca 2 RuO 4

D. Sutter, C. G. Fatuzzo, S. Moser, M. Kim, R. Fittipaldi, A. Vecchione, V. Granata, Y. Sassa, F. Cossalter, G. Gatti, M. Grioni, H. M. Rønnow, N. C. Plumb, C. E. Matt, M. Shi, M. Hoesch, T. K. Kim, T. R. Chang, H. T. Jeng, C. JozwiakA. Bostwick, E. Rotenberg, A. Georges, T. Neupert, J. Chang

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

60 Citations (Scopus)

Abstract

A paradigmatic case of multi-band Mott physics including spin-orbit and Hund's coupling is realised in Ca$_2$RuO$_4$. Progress in understanding the nature of this Mott insulating phase has been impeded by the lack of knowledge about the low-energy electronic structure. Here we provide -- using angle-resolved photoemission electron spectroscopy -- the band structure of the paramagnetic insulating phase of Ca$_2$RuO$_4$ and show how it features several distinct energy scales. Comparison to a simple analysis of atomic multiplets provides a quantitative estimate of the Hund's coupling $J=0.4$ eV. Furthermore, the experimental spectra are in good agreement with electronic structure calculations performed with Dynamical Mean-Field Theory. The crystal field stabilisation of the d$_{xy}$ orbital due to $c$-axis contraction is shown to be important in explaining the nature of the insulating state. It is thus a combination of multiband physics, Coulomb interaction and Hund's coupling that generates the Mott insulating state of Ca$_2$RuO$_4$. These results underscore the importance of Hund's coupling in the ruthenates and related multiband materials.

Original language	English
Journal	Nature Communications
Volume	8
DOIs	https://doi.org/10.1038/ncomms15176
Publication status	Published - 2017 May 5

Access to Document

10.1038/ncomms15176

http://www.mendeley.com/research/hallmarks-hunds-coupling-mott-insulator-ca-2-ruo-4

Cite this

Sutter, D., Fatuzzo, C. G., Moser, S., Kim, M., Fittipaldi, R., Vecchione, A., Granata, V., Sassa, Y., Cossalter, F., Gatti, G., Grioni, M., Rønnow, H. M., Plumb, N. C., Matt, C. E., Shi, M., Hoesch, M., Kim, T. K., Chang, T. R., Jeng, H. T., ... Chang, J. (2017). Hallmarks of Hunds coupling in the Mott insulator Ca 2 RuO 4. Nature Communications, 8. https://doi.org/10.1038/ncomms15176

@article{a66dab0bb2cf472a854078a73d485d2e,

title = "Hallmarks of Hunds coupling in the Mott insulator Ca 2 RuO 4",

abstract = "A paradigmatic case of multi-band Mott physics including spin-orbit and Hund's coupling is realised in Ca$_2$RuO$_4$. Progress in understanding the nature of this Mott insulating phase has been impeded by the lack of knowledge about the low-energy electronic structure. Here we provide -- using angle-resolved photoemission electron spectroscopy -- the band structure of the paramagnetic insulating phase of Ca$_2$RuO$_4$ and show how it features several distinct energy scales. Comparison to a simple analysis of atomic multiplets provides a quantitative estimate of the Hund's coupling $J=0.4$ eV. Furthermore, the experimental spectra are in good agreement with electronic structure calculations performed with Dynamical Mean-Field Theory. The crystal field stabilisation of the d$_{xy}$ orbital due to $c$-axis contraction is shown to be important in explaining the nature of the insulating state. It is thus a combination of multiband physics, Coulomb interaction and Hund's coupling that generates the Mott insulating state of Ca$_2$RuO$_4$. These results underscore the importance of Hund's coupling in the ruthenates and related multiband materials.",

author = "D. Sutter and Fatuzzo, {C. G.} and S. Moser and M. Kim and R. Fittipaldi and A. Vecchione and V. Granata and Y. Sassa and F. Cossalter and G. Gatti and M. Grioni and R{\o}nnow, {H. M.} and Plumb, {N. C.} and Matt, {C. E.} and M. Shi and M. Hoesch and Kim, {T. K.} and Chang, {T. R.} and Jeng, {H. T.} and C. Jozwiak and A. Bostwick and E. Rotenberg and A. Georges and T. Neupert and J. Chang",

year = "2017",

month = may,

day = "5",

doi = "10.1038/ncomms15176",

language = "English",

volume = "8",

journal = "Nature Communications",

issn = "2041-1723",

publisher = "Nature Publishing Group",

}

Sutter, D, Fatuzzo, CG, Moser, S, Kim, M, Fittipaldi, R, Vecchione, A, Granata, V, Sassa, Y, Cossalter, F, Gatti, G, Grioni, M, Rønnow, HM, Plumb, NC, Matt, CE, Shi, M, Hoesch, M, Kim, TK, Chang, TR, Jeng, HT, Jozwiak, C, Bostwick, A, Rotenberg, E, Georges, A, Neupert, T & Chang, J 2017, 'Hallmarks of Hunds coupling in the Mott insulator Ca 2 RuO 4', Nature Communications, vol. 8. https://doi.org/10.1038/ncomms15176

TY - JOUR

T1 - Hallmarks of Hunds coupling in the Mott insulator Ca 2 RuO 4

AU - Sutter, D.

AU - Fatuzzo, C. G.

AU - Moser, S.

AU - Kim, M.

AU - Fittipaldi, R.

AU - Vecchione, A.

AU - Granata, V.

AU - Sassa, Y.

AU - Cossalter, F.

AU - Gatti, G.

AU - Grioni, M.

AU - Rønnow, H. M.

AU - Plumb, N. C.

AU - Matt, C. E.

AU - Shi, M.

AU - Hoesch, M.

AU - Kim, T. K.

AU - Chang, T. R.

AU - Jeng, H. T.

AU - Jozwiak, C.

AU - Bostwick, A.

AU - Rotenberg, E.

AU - Georges, A.

AU - Neupert, T.

AU - Chang, J.

PY - 2017/5/5

Y1 - 2017/5/5

N2 - A paradigmatic case of multi-band Mott physics including spin-orbit and Hund's coupling is realised in Ca$_2$RuO$_4$. Progress in understanding the nature of this Mott insulating phase has been impeded by the lack of knowledge about the low-energy electronic structure. Here we provide -- using angle-resolved photoemission electron spectroscopy -- the band structure of the paramagnetic insulating phase of Ca$_2$RuO$_4$ and show how it features several distinct energy scales. Comparison to a simple analysis of atomic multiplets provides a quantitative estimate of the Hund's coupling $J=0.4$ eV. Furthermore, the experimental spectra are in good agreement with electronic structure calculations performed with Dynamical Mean-Field Theory. The crystal field stabilisation of the d$_{xy}$ orbital due to $c$-axis contraction is shown to be important in explaining the nature of the insulating state. It is thus a combination of multiband physics, Coulomb interaction and Hund's coupling that generates the Mott insulating state of Ca$_2$RuO$_4$. These results underscore the importance of Hund's coupling in the ruthenates and related multiband materials.

AB - A paradigmatic case of multi-band Mott physics including spin-orbit and Hund's coupling is realised in Ca$_2$RuO$_4$. Progress in understanding the nature of this Mott insulating phase has been impeded by the lack of knowledge about the low-energy electronic structure. Here we provide -- using angle-resolved photoemission electron spectroscopy -- the band structure of the paramagnetic insulating phase of Ca$_2$RuO$_4$ and show how it features several distinct energy scales. Comparison to a simple analysis of atomic multiplets provides a quantitative estimate of the Hund's coupling $J=0.4$ eV. Furthermore, the experimental spectra are in good agreement with electronic structure calculations performed with Dynamical Mean-Field Theory. The crystal field stabilisation of the d$_{xy}$ orbital due to $c$-axis contraction is shown to be important in explaining the nature of the insulating state. It is thus a combination of multiband physics, Coulomb interaction and Hund's coupling that generates the Mott insulating state of Ca$_2$RuO$_4$. These results underscore the importance of Hund's coupling in the ruthenates and related multiband materials.

U2 - 10.1038/ncomms15176

DO - 10.1038/ncomms15176

M3 - Article

SN - 2041-1723

VL - 8

JO - Nature Communications

JF - Nature Communications

ER -

Hallmarks of Hunds coupling in the Mott insulator Ca 2 RuO 4

Abstract

Access to Document

Fingerprint

Cite this