Orbital control of effective dimensionality: From spin-orbital fractionalization to confinement in the anisotropic ladder system CaCu2 O3

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Valentina Bisogni - , Leibniz Institute for Solid State and Materials Research Dresden, Paul Scherrer Institute, Brookhaven National Laboratory (Author)
  • Krzysztof Wohlfeld - , Leibniz Institute for Solid State and Materials Research Dresden, Stanford University, University of Warsaw (Author)
  • Satoshi Nishimoto - , Chair of Experimental Solid State Physics, Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • Claude Monney - , Paul Scherrer Institute, University of Zurich (Author)
  • Jan Trinckauf - , Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • Kejin Zhou - , Paul Scherrer Institute, Diamond Light Source (Author)
  • Roberto Kraus - , Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • Klaus Koepernik - , Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • Chinnathambi Sekar - , Leibniz Institute for Solid State and Materials Research Dresden, Alagappa University (Author)
  • Vladimir Strocov - , Paul Scherrer Institute (Author)
  • Bernd Büchner - , Chair of Experimental Solid State Physics, Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • Thorsten Schmitt - , Paul Scherrer Institute (Author)
  • Jeroen Van Den Brink - , Chair of Solid State Theory, Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • Jochen Geck - , Leibniz Institute for Solid State and Materials Research Dresden (Author)

Abstract

Fractionalization of an electronic quasiparticle into spin, charge, and orbital parts is a fundamental and characteristic property of interacting electrons in one dimension. However, real materials are never strictly one dimensional and the fractionalization phenomena are hard to observe. Here we studied the spin and orbital excitations of the anisotropic ladder material CaCu2O3, whose electronic structure is not one dimensional. Combining high-resolution resonant inelastic x-ray scattering experiments with theoretical model calculations, we show that (i) spin-orbital fractionalization occurs in CaCu2O3 along the leg direction x through the xz orbital channel as in a 1D system, and (ii) no fractionalization is observed for the xy orbital, which extends in both leg and rung direction, contrary to a 1D system. We conclude that the directional character of the orbital hopping can select different degrees of dimensionality. Using additional model calculations, we show that spin-orbital separation is generally far more robust than the spin-charge separation. This is not only due to the already mentioned selection realized by the orbital hopping, but also due to the fact that spinons are faster than the orbitons.

Details

Original languageEnglish
Article number096402
JournalPhysical review letters
Volume114
Issue number9
Publication statusPublished - 4 Mar 2015
Peer-reviewedYes

External IDs

PubMed 25793832
ORCID /0000-0002-2438-0672/work/158767774

Keywords

ASJC Scopus subject areas