Full Counting Statistics for Orbital-Degenerate Impurity Anderson Model with Hund’s Rule Exchange Coupling
File(s)Physical Review Letters_108_26_2012.pdf (130.38 KB)
Accepted version
Author(s)
Sakano, R
Nishikawa, Y
Oguri, A
Hewson, AC
Tarucha, S
Type
Journal Article
Abstract
We study nonequilibrium current fluctuations through a quantum dot, which includes a ferromagnetic Hund’s rule coupling J, in the low-energy Fermi liquid regime using the renormalized perturbation theory. The resulting cumulant for the current distribution in the particle-hole symmetric case shows that spin-triplet and spin-singlet pairs of quasiparticles are formed in the current due to the Hund’s rule coupling, and these pairs enhance the current fluctuations. In the fully screened higher-spin Kondo limit, the Fano factor takes a value Fb=(9M+6)/(5M+4) determined by the orbital degeneracy M. We also investigate the crossover between the small and large J limits in the two-orbital case M=2, using the numerical renormalization group approach.
Date Issued
2012-06
Citation
Physical Review Letters, 2012, 108 (26), pp.266401-
ISSN
0031-9007
Publisher
AMER PHYSICAL SOC
Start Page
266401
Journal / Book Title
Physical Review Letters
Volume
108
Issue
26
Copyright Statement
© 2012 American Physical Society
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000305689400028&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
ARTN 266401
Publication Status
Published