Stanford
Shen Laboratory

Strontium Ruthenate

 
Band mapping of Sr2RhO4 as revealed by ARPES measurements.

Strontium ruthenate compounds were initially thought to be related to high-Tc superconductors: their physics are highly two-dimensional, and the crystal structure of Sr2RuO4 is almost identical to that of (La,Sr)2CuO4. Furthermore, both materials are oxides with conduction occurring in partially filled d-bands (of strontium or copper ions) that are strongly hybridized with the p orbitals of oxygen ions.

However, in Sr2RuO4, superconductivity appears only at low temperatures (1.5 K), in samples with very low residual resistivity, and out of a normal state that is a well-formed Fermi liquid, hence putting them in a different regime than high-Tc superconductors — especially as opposed to the strange metal state present in many cuprates. ARPES investigations concentrated on providing evidence for the prototypical Fermi liquid nature of the strontium-ruthenate compounds, and mapping the rich band structure of this complex material. Results agreed remarkably with de Haas-van Alphen quantum oscillation measurements. As strontium-rhodium compounds also allow a clean mapping of the band structure and exhibit strong Fermi-liquid behavior, they have tbecome a great testing ground for theoretical predictions.

Selected Publications

  1. A. Damascelli et al. Fermi surfaces, surface states, and surface reconstruction in Sr2RuO4. Phys. Rev. Lett. 85, 5194 (2000)
  2. F. Baumberger et al. Nested Fermi surface and electronic instability in Ca3Ru2O7. Phys. Rev. Lett. 96, 107601 (2006)
  3. F. Baumberger et al. Fermi surface and quasiparticle excitations of Sr2RhO4. Phys. Rev. Lett. 96, 246402 (2006)