Singlet-triplet excitations in the unconventional spin-Peierls TiOBr compound.

نویسندگان

  • J P Clancy
  • B D Gaulin
  • C P Adams
  • G E Granroth
  • A I Kolesnikov
  • T E Sherline
  • F C Chou
چکیده

We have performed time-of-flight neutron scattering measurements on powder samples of the unconventional spin-Peierls compound TiOBr using the fine-resolution Fermi chopper spectrometer (SEQUOIA) at the Spallation Neutron Source at Oak Ridge National Laboratory. These measurements reveal two branches of magnetic excitations within the commensurate and incommensurate spin-Peierls phases, which we associate with n=1 and n=2 triplet excitations out of the singlet ground state. These results represent the first direct measurement of the singlet-triplet energy gap in TiOBr, which has a value of E(g)=21.2±1.0  meV.

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عنوان ژورنال:
  • Physical review letters

دوره 106 11  شماره 

صفحات  -

تاریخ انتشار 2011