Magnetism in CeRhIn$_5$ at high fields measured by NMR
ORAL
Abstract
De Haas-van Alphen measurements[1] of CeRhIn$_5$ at ambient pressure show an abrupt change in the Fermi surface volume at high fields, $H^* \approx$ 30 T, and low temperatures resulting in antiferromagnetic phases with a small Fermi surface at fields below $H^*$ and a large Fermi surface at fields $H$ such that $H^* < H < 50$ T. Nuclear magnetic resonance (NMR) is the ideal probe for these magnetic states as the microscopic details are still lacking. Our preliminary NMR measurements find the magnetic order for $H\parallel c$ is incommensurate up to 30 T as opposed to $H \perp c$ which transitions from incommensurate to commensurate at $H \approx$ 2 T.[2] Furthermore, we find that the magnetic moment decreases near 17 T for $H \parallel c$. These measurements provide an insight into the magnetic anisotropy of CeRhIn$_5$ and are a crucial step to studying its high field phases. [1] L. Jiao et al., arXiv 1308.0294. [2] S. Raymond et al., J. Phys. Cond. Matt. 19, 242204 (2007).
*Work at Los Alamos was performed under the auspices of the U.S. DOE, Office of Basic Energy Science, Division of Materials and Engineering.
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