Kondo screening in a charge-insulating spinon metal
arXiv:1904.06506 · doi:10.1038/s41567-019-0536-2
Abstract
The Kondo effect, an eminent manifestation of many-body physics in condensed matter, is traditionally explained as exchange scattering of conduction electrons on a spinful impurity in a metal. The resulting screening of the impurity's local moment by the electron Fermi sea is characterized by a Kondo temperature , below which the system enters a non-perturbative strongly-coupled regime. In recent years, this effect has found its realizations beyond the bulk-metal paradigm in many other itinerant-electron systems, such as quantum dots in semiconductor heterostructures and in nanomaterials, quantum point contacts, and graphene. Here we report on the first experimental observation of the Kondo screening by chargeless quasiparticles. This occurs in a charge-insulating quantum spin liquid, where spinon excitations forming a Fermi surface take the role of conduction electrons. The observed impurity behaviour therefore bears a strong resemblance to the conventional case in a metal. The discovered spinon-based Kondo effect provides a prominent platform for characterising and possibly manipulating enigmatic host spin liquids.
accepted for publication in Nature Physics
References in corpus (10)
- Continuous excitations of the triangular-lattice quantum spin liquid YbMgGaO4
- Sum-rule Conserving Spectral Functions from the Numerical Renormalization Group
- The Kondo effect in C single-molecule transistors
- Are non-Fermi-liquids stable to Cooper pairing?
- Energy resolution and discretization artefacts in the numerical renormalization group
- The Physics of Kondo Impurities in Graphene
- Theory of quantum impurities in spin liquids
- Mean Field study of the heavy fermion metamagnetic transition
- Field-Induced Instability of a Gapless Spin Liquid with a Spinon Fermi Surface
- The magneto-optical Faraday effect in spin liquid candidates