Spin Correlations of Quantum Spin Liquid and Quadrupole-Ordered States of Tb2+xTi2-xO7+y

Published

January 7, 2019

Author(s)

Hiroaki Kadowaki, Mika Wakita, Bjorn Fak, Jacques Ollivier, Seiko Ohira-Kawamura, Kenji Nakajima, Jeffrey W. Lynn

Abstract

Spin correlations of the frustrated pyrochlore oxide Tb_2+xTi_2-xO_7+y have been investigated by using inelastic neutron scattering on single crystalline samples (x = -0.007, 0.000, and 0.003), which have the putative quantum-spin-liquid (QSL) or electric-quadrupolar ground states. Spin correlations, which are notable obeserved in nominally elastic scattering, show short-ranged correlations around L points [q = (1/2, 1/2, 1/2)], tiny antiferromagnetic Bragg scattering at L and Γ points. The short-ranged spin correlations were analyzed using a random phase approximation (RPA) assuming the paramagnetic state and two-spin interactions among Ising spins. These analyses have shown that the RPA scattering intensity well reproduces the experimental data using temperature and x dependent coupling constants of up to 10th neighbor site pairs. This suggests that no symmetry breaking occurs in the QSL sample, and that a quantum treatment beyond the semi-classical RPA approach is required. Implications of the experimental data and the RPA analyses are discussed.

Citation

Physical Review B

Volume

99

Issue

1

Pub Type

Journals

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Keywords

Spin Liquid, Quadrupole Order, pyrochlore

Citation

Kadowaki, H. , Wakita, M. , Fak, B. , Ollivier, J. , Ohira-Kawamura, S. , Nakajima, K. and Lynn, J. (2019), Spin Correlations of Quantum Spin Liquid and Quadrupole-Ordered States of Tb_2+xTi_2-xO_7+y, Physical Review B, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=926694 (Accessed April 25, 2024)