Occupied and unoccupied electronic states in a layered perovskite superconductor without copper: band dispersions, van Hove singularity, and hole states in Sr2RuO4

Tom R. Cummins; Michael S. Schmidt; Dong Hui Lu; Martin Buerk; Stefan Schuppler; F. Litchenburg; J. Georg Bednorz

doi:10.1117/12.241787

10 June 1996 Occupied and unoccupied electronic states in a layered perovskite superconductor without copper: band dispersions, van Hove singularity, and hole states in Sr₂RuO₄

Tom R. Cummins, Michael S. Schmidt, Dong Hui Lu, Martin Buerk, Stefan Schuppler, F. Litchenburg, J. Georg Bednorz

Author Affiliations +

Proceedings Volume 2696, Spectroscopic Studies of Superconductors; (1996) https://doi.org/10.1117/12.241787
Event: Photonics West '96, 1996, San Jose, CA, United States

Abstract

The occupied and unoccupied electronic structure of high quality single crystals of the copper- free layered perovskite superconductor Sr₂RuO₄ has been measured for the first time. Angle-resolved photoemission spectroscopy with high energy and angle resolution determined band dispersions along the principle directions of the projected Brillouin zone of the (001) surface. The highlight of these spectra is the observation and characterization of an extended van Hove singularity. The singularity is located 17 meV below the Fermi level and extends around the M point for around 0.2 angstrom^-1 along both (Gamma) -M-Gamma and X-M-X. Dispersions of the near-Fermi level states in Sr₂RuO₄ reveal 3 bands which cross the Fermi level giving rise to 3 Fermi surfaces; 1 electron-like Fermi surface around the (Gamma) point and 2 hole-like surfaces encircling the X point. The topology of the empirically determined Fermi surfaces is found to be in qualitative agreement with local density approximation band structure calculations. Photoemission of the full valence band of Sr₂RuO₄ are also presented. The total valence band width is approximately 9 eV, the density of states at the Fermi level derived from photoemission is 1.3 states/(eV cell) and has an 80%/20% mix of metal to ligand character. Polarization-dependent O1s NEXAFS performed on Sr₂RuO₄ demonstrate mainly hole states at the Fermi level in orbitals in the RuO₂ planes. Electron correlations among Ru 4d levels in Sr₂RuO₄ are argued to have a lesser impact than that of 3d levels in the cuprates.

Citation Download Citation

Tom R. Cummins, Michael S. Schmidt, Dong Hui Lu, Martin Buerk, Stefan Schuppler, F. Litchenburg, and J. Georg Bednorz "Occupied and unoccupied electronic states in a layered perovskite superconductor without copper: band dispersions, van Hove singularity, and hole states in Sr₂RuO₄", Proc. SPIE 2696, Spectroscopic Studies of Superconductors, (10 June 1996); https://doi.org/10.1117/12.241787

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members: $17.00

Non-members: $21.00 ADD TO CART

PROCEEDINGS
11 PAGES

DOWNLOAD PAPER SAVE TO MY LIBRARY

GET CITATION

RIGHTS & PERMISSIONS

Get copyright permission Get copyright permission on Copyright Marketplace

KEYWORDS

Information technology

Superconductors

Ruthenium

Crystals

Copper

Perovskite

Photoemission spectroscopy

Show All Keywords

Keywords/Phrases

Search In:

Publication Years