Abstract
is a Kondo-lattice prototype in which a magnetic field induces an abrupt Fermi-surface (FS) reconstruction and pronounced in-plane electrical transport anisotropy all within its antiferromagnetic state. Though the antiferromagnetic order at zero field is well understood, the origin of an emergent state at remains unknown due to challenges inherent to probing states microscopically at high fields. Here we report low-temperature nuclear magnetic resonance (NMR) measurements revealing a pronounced decrease in the formal Knight shift, without changes in crystal or magnetic structures, of at fields () spanning . We discuss the emergent state above in terms of a change in Ce's orbitals that arises from field-induced evolution of crystal-electric field (CEF) energy levels. This change in orbital character enhances hybridization between the and the conduction electrons that leads ultimately to an itinerant quantum-critical point at .
- Received 12 June 2019
- Revised 12 March 2020
- Accepted 13 March 2020
DOI:https://doi.org/10.1103/PhysRevB.101.165111
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