Singlet-to-Triplet Excitations in the Unconventional Spin-Peierls System TiOBr

Journal Article · Sat Jan 01 00:00:00 EST 2011 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.106.117401· OSTI ID:1009481

Clancy, James P ^[1]; Gaulin, Bruce D. ^[1]; Adams, Carl P ^[2]; Granroth, Garrett E ^[3]; Kolesnikov, Alexander I ^[3]; Sherline, Todd E ^[3]; Chou, F. C. ^[4]

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1. McMaster University
2. St. Francis Xavier University, Antigonish, Nova Scotia
3. ORNL
4. National Taiwan University

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 SNS. 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 measurements represent the first direct measure of the singlet-triplet energy gap in TiOBr, which is found to have a value of Eg 21 meV.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1009481
• Journal Information: Physical Review Letters, Vol. 106, Issue 11; ISSN 0031--9007
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ENERGY GAP
GROUND STATES
NEUTRONS
SCATTERING
SPECTROMETERS
TRIPLETS