Neutron scattering and mu SR investigations of the low temperature state of LuCuGaO₄

TY - JOUR

T1 - Neutron scattering and mu SR investigations of the low temperature state of LuCuGaO4

AU - Calder, S.

AU - Giblin, S. R.

AU - Parker, D. R.

AU - Deen, P. P.

AU - Ritter, C.

AU - Stewart, J. R.

AU - Rols, S.

AU - Fennell, T.

PY - 2013/9/4

Y1 - 2013/9/4

N2 - LuCuGaO4 has magnetic Cu2+ and diamagnetic Ga 3+ ions distributed on a triangular bilayer and is suggested to undergo a spin glass transition at Tg ∼ 0.4 K. Using μSR (muon spin rotation) and neutron scattering measurements, we show that at low temperature the spins form a short range correlated state with spin fluctuations detectable over a wide range of timescales: at 0.05 K magnetic fluctuations can be detected in both the μSR time window and also extending beyond 7 meV in the inelastic neutron scattering response, indicating magnetic fluctuations spanning timescales between ∼10-5 and ∼10-10 s. The dynamical susceptibility scales according to the form χ″(ω) Tα, with α = 1, throughout the measured temperature range (0.05-50 K). These effects are associated with quantum fluctuations and some degree of structural disorder in ostensibly quite different materials, including certain heavy fermion alloys, kagome spin liquids, quantum spin glasses, and valence bond glasses. We therefore suggest that LuCuGaO4 is an interesting model compound for the further examination of disorder and quantum magnetism.

AB - LuCuGaO4 has magnetic Cu2+ and diamagnetic Ga 3+ ions distributed on a triangular bilayer and is suggested to undergo a spin glass transition at Tg ∼ 0.4 K. Using μSR (muon spin rotation) and neutron scattering measurements, we show that at low temperature the spins form a short range correlated state with spin fluctuations detectable over a wide range of timescales: at 0.05 K magnetic fluctuations can be detected in both the μSR time window and also extending beyond 7 meV in the inelastic neutron scattering response, indicating magnetic fluctuations spanning timescales between ∼10-5 and ∼10-10 s. The dynamical susceptibility scales according to the form χ″(ω) Tα, with α = 1, throughout the measured temperature range (0.05-50 K). These effects are associated with quantum fluctuations and some degree of structural disorder in ostensibly quite different materials, including certain heavy fermion alloys, kagome spin liquids, quantum spin glasses, and valence bond glasses. We therefore suggest that LuCuGaO4 is an interesting model compound for the further examination of disorder and quantum magnetism.

U2 - 10.1088/0953-8984/25/35/356002

DO - 10.1088/0953-8984/25/35/356002

M3 - Journal article

SN - 0953-8984

VL - 25

JO - Journal of Physics: Condensed Matter

JF - Journal of Physics: Condensed Matter

IS - 35

M1 - 356002

ER -