Bulk- and surface-sensitive high-resolution photoemission study of two mott-hubbard systems: SrVO3 and CaVO3.

We study the electronic structure of Mott-Hubbard systems SrVO3 and CaVO3 with bulk and surface-sensitive high-resolution photoemission spectroscopy, using a vacuum ultraviolet laser, synchrotron radiation, and a discharge lamp (hv = 7-21 eV). A systematic suppression of the density of states (DOS) within approximately 0.2 eV of the Fermi level (EF) is found on decreasing photon energy, i.e., on increasing bulk sensitivity. The coherent band in SrVO3 and CaVO3 is shown to consist of surface and bulk-derived features, separated in energy. The stronger distortion on surface of CaVO3 compared to SrVO3 leads to a higher surface metallicity in the coherent DOS at EF, consistent with recent theory.

[1]  T. Togashi,et al.  Photoemission spectroscopic evidence of gap anisotropy in an f-electron superconductor. , 2005, Physical review letters.

[2]  I. A. Nekrasov,et al.  Comparative study of correlation effects in CaVO3 and SrVO3 , 2005, cond-mat/0501240.

[3]  Satoshi Okamoto,et al.  Electronic reconstruction at an interface between a Mott insulator and a band insulator , 2004, Nature.

[4]  Akira Ohtomo,et al.  A high-mobility electron gas at the LaAlO3/SrTiO3 heterointerface , 2004, Nature.

[5]  D. E. Kondakov,et al.  Mutual experimental and theoretical validation of bulk photoemission spectra of Sr1-xCaxVO3. , 2003, Physical review letters.

[6]  A. Georges,et al.  Mott transition and suppression of orbital fluctuations in orthorhombic 3d1 perovskites. , 2003, Physical review letters.

[7]  K. Nasu,et al.  Intermediately Correlated Many-electron Systems Studied by Quantum Monte Carlo Method , 2003 .

[8]  K. Nasu,et al.  Path-integral theory of the metal-insulator transition in the three-dimensional Hubbard model , 2003 .

[9]  M. Potthoff,et al.  Correlation and surface effects in vanadium oxides , 2003, cond-mat/0302427.

[10]  Chengqian Zhang,et al.  Generation of vacuum-ultraviolet light by an optically contacted, prism-coupled KBe2BO3F2 crystal. , 2003, Optics letters.

[11]  A. Liebsch.  Surface versus bulk Coulomb correlations in photoemission spectra of SrVO3 and CaVO3. , 2002, Physical review letters.

[12]  Akira Ohtomo,et al.  Artificial charge-modulationin atomic-scale perovskite titanate superlattices , 2002, Nature.

[13]  M. Arita,et al.  HIGH-RESOLUTION AND LOW-TEMPERATURE PHOTOEMISSION SPECTROSCOPY AT THE HISOR HELICAL-UNDULATOR BEAMLINE , 2002 .

[14]  K. Shirasawa,et al.  off-plane Eagle monochromator at the helical undulator beamline of HiSOR , 2001 .

[15]  D. Sarma,et al.  Electronic structure of Ca1 − xSrxVO3: A tale of two energy scales , 2001, cond-mat/0105424.

[16]  M. Potthoff,et al.  Metallic surface of a Mott insulator-Mott insulating surface of a metal , 1999, cond-mat/9906412.

[17]  Masatoshi Imada,et al.  Metal-insulator transitions , 1998 .

[18]  J. Ghijsen,et al.  The Hiroshima Synchrotron Radiation Center (HSRC). , 1998, Journal of synchrotron radiation.

[19]  I. Inoue,et al.  Bandwidth control in a perovskite-type 3 d 1 -correlated metal Ca 1 − x Sr x VO 3 . I. Evolution of the electronic properties and effective mass , 1998, cond-mat/9801073.

[20]  Kobayashi,et al.  Spectral weight transfer and mass renormalization in Mott-Hubbard systems SrVO3 and CaVO3: Influence of long-range Coulomb interaction. , 1995, Physical review. B, Condensed matter.

[21]  Thomas,et al.  Optical conductivity in Mott-Hubbard systems. , 1995, Physical review letters.

[22]  Inoue,et al.  Systematic development of the spectral function in the 3d1 Mott-Hubbard system Ca1-xSrxVO3. , 1995, Physical review letters.

[23]  Tokura,et al.  Anomalous variation of phonon Raman intensities near the metal-to-Mott-insulator transition in titanium oxide systems. , 1994, Physical review. B, Condensed matter.

[24]  K. Takegahara.  Electronic band structures in cubic perovskite-type oxides: bismuthates and transition metal oxides , 1994 .

[25]  E. Dagotto.  Correlated electrons in high-temperature superconductors , 1993, cond-mat/9311013.

[26]  Zhang,et al.  Mott transition in the d= , 1993, Physical review letters.

[27]  Hase,et al.  Evolution of the spectral function in Mott-Hubbard systems with d1 configuration. , 1992, Physical review letters.

[28]  Liu,et al.  alpha - gamma transition in Ce: A detailed analysis of electron spectroscopy. , 1992, Physical review. B, Condensed matter.

[29]  Greedan,et al.  Reflectance and resistivity of barely metallic LaTiO3. , 1991, Physical review. B, Condensed matter.

[30]  Kampf,et al.  Pseudogaps and the spin-bag approach to high-Tc superconductivity. , 1990, Physical review. B, Condensed matter.

[31]  T. M. Rice,et al.  A Charge-Density-Wave Instability in BaBi1-xPbxO3 Caused by Strong Electron-Phonon Coupling , 1986 .

[32]  W. A. Dench,et al.  Quantitative electron spectroscopy of surfaces: A standard data base for electron inelastic mean free paths in solids , 1979 .

[33]  B. Chamberland,et al.  Alkaline-earth vanadium (IV) oxides having the AVO3 composition , 1971 .

[34]  A. S. Barker.  Temperature Dependence of the Transverse and Longitudinal Optic Mode Frequencies and Charges in SrTiO 3 and BaTiO 3 , 1966 .

[35]  J. Hubbard.  Electron correlations in narrow energy bands , 1963, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.