Angle-resolved photoemission spectroscopy of the insulating NaxWO3: Anderson localization, polaron formation, and remnant Fermi surface.

The electronic structure of the insulating sodium tungsten bronze, Na(0.025)WO(3), is investigated by high-resolution angle-resolved photoemission spectroscopy. We find that near-E(F) states are localized due to the strong disorder arising from random distribution of Na+ ions in the WO(3) lattice, which makes the system insulating. The temperature dependence of photoemission spectra provides direct evidence for polaron formation. The remnant Fermi surface of the insulator is found to be the replica of the real Fermi surface in the metallic system.

[1]  H. Matsui,et al.  Angle-resolved photoemission spectroscopy of the metallic sodium tungsten bronzes $Na_{x}WO_{3}$ , 2005 .

[2]  Ismail,et al.  Ferromagnetism stabilized by lattice distortion at the surface of the p-wave superconductor Sr(2)RuO(4) , 2000, Science.

[3]  S. Reich,et al.  Possible nucleation of a 2D superconducting phase on WO single crystals surface doped with Na , 1999 .

[4]  G. Kresse,et al.  From ultrasoft pseudopotentials to the projector augmented-wave method , 1999 .

[5]  Shen,et al.  Photoemission evidence for a remnant fermi surface and a d-wave-like dispersion in insulating Ca2CuO2Cl2 , 1998, Science.

[6]  A. Millis.  Lattice effects in magnetoresistive manganese perovskites , 1998, Nature.

[7]  Kresse,et al.  Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. , 1996, Physical review. B, Condensed matter.

[8]  G. Kresse,et al.  Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set , 1996 .

[9]  Blöchl,et al.  Projector augmented-wave method. , 1994, Physical review. B, Condensed matter.

[10]  T. R. Kirkpatrick,et al.  The Anderson-Mott transition , 1994 .

[11]  Ranninger,et al.  Two-site polaron problem: Electronic and vibrational properties. , 1992, Physical review. B, Condensed matter.

[12]  R. Egdell,et al.  Evidence for polaronic states in Na0.1WO3 from Raman scattering , 1989 .

[13]  Löwen.  Absence of phase transitions in Holstein systems. , 1988, Physical review. B, Condensed matter.

[14]  Himpsel,et al.  Metal-nonmetal transition in tungsten bronzes: A photoemission study. , 1985, Physical review. B, Condensed matter.

[15]  E. Salje,et al.  Anderson transition and intermediate polaron formation in WO3-xTransport properties and optical absorption , 1984 .

[16]  G. Bergmann,et al.  Weak localization in thin films: a time-of-flight experiment with conduction electrons , 1984 .

[17]  M. D. Hill,et al.  The sodium tungsten bronzes: a study of the changes in electronic structure with composition using high-resolution electron spectroscopy , 1983 .

[18]  G. Bergmann,et al.  Physical interpretation of weak localization: A time-of-flight experiment with conduction electrons , 1983 .

[19]  De Raedt,et al.  Numerical calculation of path integrals: The small-polaron model , 1983 .

[20]  E. Salje,et al.  Conduction bipolarons in low-temperature crystalline WO3-x , 1980 .

[21]  Z. Hurych,et al.  Vacuum ultraviolet-photoemission study of some sodium tungsten bronzes, Na x WO 3 , 1978 .

[22]  E. Sonder,et al.  MAGNETIC PROPERTIES OF N-TYPE SILICON , 1958 .

[23]  P. Anderson.  Absence of Diffusion in Certain Random Lattices , 1958 .

[24]  N F Mott,et al.  The Basis of the Electron Theory of Metals, with Special Reference to the Transition Metals , 1949 .

[25]  E. Salje,et al.  Polarons and Bipolarons in High-TcSuperconductors and Related Materials , 1995 .

[26]  E. Salje,et al.  The W5+ polaron in crystalline low temperature WO3 ESR and optical absorption , 1980 .

[27]  N. Mott.  The degenerate electron gas in tungsten bronzes and in highly doped silicon , 1977 .