Tunneling through a Quantum Dot in Local Spin Singlet-Triplet Crossover Region with Kondo Effect

Wataru Izumida; Osamu Sakai; Seigo Tarucha

doi:10.1103/PhysRevLett.87.216803

Tunneling through a Quantum Dot in Local Spin Singlet-Triplet Crossover Region with Kondo Effect

Wataru Izumida, Osamu Sakai, and Seigo Tarucha

Phys. Rev. Lett. 87, 216803 – Published 1 November 2001

Abstract

Tunneling conductance through a quantum dot is calculated around the local spin singlet-triplet crossover region including the Kondo effect. The calculation is carried out using the numerical renormalization group method. When the potential on the dot deepens, two electrons filling a lower energy orbital redistribute to gain Hund’s coupling energy. This redistribution induces a bump in the conductance between the Coulomb peaks. The Kondo temperature on the bump is high due to the fluctuation on the singlet-triplet crossover region. The behaviors agree well with recent experiment.

Received 17 May 2001

DOI:https://doi.org/10.1103/PhysRevLett.87.216803

Authors & Affiliations

Wataru Izumida¹, Osamu Sakai², and Seigo Tarucha^1,3,4

¹Mesoscopic Correlation Project, ERATO, JST, NTT Atsugi R & D Center, Atsugi-shi, Kanagawa 243-0198, Japan
²Department of Physics, Tokyo Metropolitan University, Tokyo 192-0397, Japan
³Department of Physics, University of Tokyo, Tokyo 113-0033, Japan
⁴NTT Basic Research Laboratories, Atsugi-shi, Kanagawa 243-0129, Japan