Fermi Surface Nesting in CeIn<sub>3</sub> Revealed by Neutron Spectroscopy
ORAL
Abstract
We report a high-resolution neutron spectroscopy study of the archetypal heavy fermion material CeIn3 that exhibits an antiferromagnetic ground state below TN = 10.1 K with a commensurate propagation vector k = (½, ½, ½). Previous neutron results with moderate energy resolution reported a substantial spin gap of 1.3 meV, which suggest large magnetic anisotropy even though this is not supported by the observed bulk properties. Our results unambiguously demonstrate that CeIn3 does not exhibit a spin gap. Instead, we find that the spin waves disperse quasi-vertically up to almost 1 meV. When such as steep dispersion is probed with not sufficiently high resolution, this will result in an artifact in the neutron spectrum that looks like a spin gap, and thus our findings are in agreement with previous reports. More interestingly, the steep spin wave dispersion of CeIn3 reveals truly long-range magnetic exchange interactions and suggests Fermi surface nesting.
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Presenters
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Marc Janoschek
- Los Alamos National Laboratory
- Los Alamos Natl Lab
- MPA-CMMS, Los Alamos National Lab