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High-Energy Spin Dynamics in La$_{1.69}$Sr$_{0.31}$NiO$_4$

P. Bourges·Y. Sidis·M. Braden·K. Nakajima·J. M. Tranquada
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Abstract

We have mapped out the spin dynamics in a stripe-ordered nickelate, La$_{2-x}$Sr$_{x}$NiO$_{4}$ with $x \simeq 0.31$, using inelastic neutron scattering. We observe spin-wave excitations up to 80 meV emerging from the incommensurate magnetic peaks with an almost isotropic spin-velocity: $\hbar c_s\sim 0.32$ eV Å, very similar to the velocity in the undoped, insulating parent compound, La$_{2}$NiO$_{4}$. We also discuss the similarities and differences of the inferred spin-excitation spectrum with those reported in superconducting high-$T_c$ cuprates.

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P. Bourges, Y. Sidis, M. Braden, K. Nakajima, J. M. Tranquada. 2002-03-08. High-Energy Spin Dynamics in La$_{1.69}$Sr$_{0.31}$NiO$_4$. https://doi.org/10.1103/physrevlett.90.147202

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