Mott to Kondo transition in Kondo lattices

Lead Research Organisation: King's College London
Department Name: Physics

Abstract

Recent experiments preformed on the deposition of f elements upon metallic substrates have generated a tremendous interest in the scientific community due to the resultant self-assembled f element superlattices. In particular, this has opened avenues towards an experimental realization of Kondo lattices.
A number of self-assembled structures have been discovered, however no clear theoretical description has so far provided a classification of the Mott and Kondo physics of the experiments. In this work we provide a general phase diagram of correlated super-structures as a function of correlation strength, substrate electronic density, and adatom inter-distances. Through the use of state-of-the-art dynamical mean-field theory calculations at finite temperature, we have identified a clear regime of parameters where Kondo lattices can be realised. We also report a sharp transition between Mott type physics (for short adatom inter-distances) and Kondo physics. We also report the stabilization of a charge density wave competing with Kondo physics at large inter-adatom distances. Finally, for half-filled f occupation the ionic potential of the f element induces a non trivial bound state between the f and substrate electrons, which in turn is unaffected by the local many-body effects present within the f-shell.

Publications

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Lee H (2019) The Mott to Kondo transition in diluted Kondo superlattices in Communications Physics

Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/N509498/1 01/10/2016 30/09/2021
1949871 Studentship EP/N509498/1 01/10/2017 31/08/2021 Hovan Lee
 
Description Both Mott insulators and Kondo scattering are effects of localised electrons in correlated materials. If these effects are examined in the point of view of the localised electron orbitals in the material, Mott transition arises from the charge degree of freedom, whereas Kondo scattering is a result of the spin degree of freedom.

This work is the first to describe a pathway between the two effects through the modelling of a system of superlattices with correlated impurities (Kondo superlattices) with both spin and charge degrees of freedom. Allowing for single atom magnetic moment (and hence single atom memory storage) in a lattice structure (such as the Ce/Ag(111) system in a related work) to become a reality.
Exploitation Route The real world applications of this work could help pave way for future spintronics, quantum computers and high density memory storage at the localised electron orbitals. The critical point is that these localised orbitals all at a set distance from each other, allowing for predictable spatial locations for the reading/ writing of magnetic states.
Sectors Digital/Communication/Information Technologies (including Software),Electronics,Manufacturing, including Industrial Biotechology

URL https://www.nature.com/articles/s42005-019-0146-4