Valence skipping phenomena, charge Kondo effect, and superconductivity

We review a recent progress of a superconductivity and a charge Kondo effect mediated by valence skippers which are elements skipping the valence state. To understand the valence skipping phenomenon, we introduce a negative-U effect phenomenologically, and we show an origin of the negative-U effect,...

Full description

Saved in:
Bibliographic Details
Published in:AAPPS bulletin 2022-09, Vol.32 (1), p.1-18, Article 30
Main Authors: Matsuura, Hiroyasu, Mukuda, Hidekazu, Miyake, Kazumasa
Format: Article
Language:English
Subjects:
Astronomy
Astrophysics and Cosmology
Atomic
Molecular
Optical and Plasma Physics
Particle and Nuclear Physics
Physics
Physics and Astronomy
Review Article
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We review a recent progress of a superconductivity and a charge Kondo effect mediated by valence skippers which are elements skipping the valence state. To understand the valence skipping phenomenon, we introduce a negative-U effect phenomenologically, and we show an origin of the negative-U effect, a superconductivity and charge Kondo effect based on the negative-U effect. We also show a new mechanism in which the valence skipping phenomenon and charge Kondo effect are understood unifiedly by the pair hopping interaction. As an experimental progress, we review a charge Kondo effect and a superconductivity discovered in Tl-doped PbTe. Especially, we focus on a drastic increase of the inverse of the relaxation time (1/ T 1 ) observed around the Kondo temperature by the nuclear magnetic resonance experiment, and we suggest a possible theoretical scenario on the basis of the effective model with the pair hopping interaction. Finally, we discuss the related materials, and describe the perspective of valence skipping phenomenon.
ISSN:2309-4710
2309-4710
DOI:10.1007/s43673-022-00056-1