Ring-exchange interaction in doubly degenerate orbital system

Joji Nasu, Sumio Ishihara

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


The ring-exchange (RE) interaction in a Mott insulator with doubly degenerate eg orbitals is studied. The Hamiltonian for the RE interaction is derived by a perturbational calculation. A remarkably weak RE interaction destroys the orbital order caused by the order-by-fluctuation mechanism in the nearest-neighbor exchange-interaction model. A magnetic octupole moment with long range order, i.e., complex orbital wave functions, appears. Competition between octupole and quadrupole interactions strongly suppresses the ordered moments.

Original languageEnglish
Article number033704
Journaljournal of the physical society of japan
Issue number3
Publication statusPublished - 2011 Mar


  • Frustration
  • Octupole order
  • Orbital order
  • Ring-exchange interaction

ASJC Scopus subject areas

  • Physics and Astronomy(all)


Dive into the research topics of 'Ring-exchange interaction in doubly degenerate orbital system'. Together they form a unique fingerprint.

Cite this