Inverse Isotope Effect on Kondo Temperature in ElectronRattling System
Abstract
In an electron system coupled with anharmonic phonons, i.e., rattling, inverse isotope effect on the Kondo temperature T_{K} is found to occur by the numerical evaluation of the Sommerfeld constant γ of the AndersonHolstein model. For the anharmonic potential of an oscillator with mass M in which large γ has been found to be almost independent of an applied magnetic field, γ is significantly suppressed when M is increased, i.e., T_{K} is enhanced due to the relation of γ∼ T_{K}^{1} in the Kondo problem, leading to the inverse isotope effect on T_{K}. Since this phenomenon does not occur for harmonic phonons, it can be a key experiment to prove the relevance of rattling to magnetically robust heavy electron state.
 Publication:

Journal of the Physical Society of Japan
 Pub Date:
 July 2009
 DOI:
 10.1143/JPSJ.78.073707
 arXiv:
 arXiv:0906.0815
 Bibcode:
 2009JPSJ...78g3707H
 Keywords:

 Condensed Matter  Strongly Correlated Electrons;
 Condensed Matter  Materials Science
 EPrint:
 4 pages, 3 figures. To appear in J. Phys. Soc. Jpn