Spin ice: magnetic excitations without monopole signatures using muon spin rotation

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

DOI:https://doi.org/10.1103/PhysRevLett.107.207207· OSTI ID:1034014

Dunsiger, Sarah ^[1]; Aczel, Adam A. ^[2]; Arguello, Carlos ^[3]; Dabkowska, H. A. ^[2]; Dabkowski, A ^[2]; Du, Mao-Hua ^[4]; Goko, Tatsuo ^[3]; Javanparast, B ^[5]; Lin, T ^[5]; Ning, F. L. ^[2]; Noad, H. M. ^[2]; Singh, David J ^[4]; Williams, T. J. ^[2]; Uemura, Yasutomo J. ^[3]; Gingras, M. P.J. ^[5]; Luke, Graeme M. ^[2]

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1. Technical University, Munich, Germany
2. McMaster University
3. Columbia University
4. ORNL
5. University of Waterloo, Canada

Theory predicts the low temperature magnetic excitations in spin ices consist of deconfined magnetic charges, or monopoles. A recent transverse-field (TF) muon spin rotation ({mu}SR) experiment [S.T. Bramwell et al., Nature (London) 461 956 (2009)] reports results claiming to be consistent with the temperature and magnetic field dependence anticipated for monopole nucleation - the so-called second Wien effect. We demonstrate via a new series of {mu}SR experiments in Dy{sub 2}Ti{sub 2}O{sub 7} that such an effect is not observable in a TF {mu}SR experiment. Rather, as found in many highly frustrated magnetic materials, we observe spin fluctuations which become temperature independent at low temperatures, behavior which dominates over any possible signature of thermally nucleated monopole excitations.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1034014
• Journal Information: Physical Review Letters, Vol. 107, Issue 20; ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
FLUCTUATIONS
MAGNETIC FIELDS
MAGNETIC MATERIALS
MONOPOLES
MUON SPIN RELAXATION
NUCLEATION
SPIN