Two-impurity kondo effect in double-quantum-dot systems: Effect of interdot kinetic exchange coupling

Wataru Izumida, Osamu Sakai

Research output: Contribution to journalArticlepeer-review

112 Citations (Scopus)


Tunneling conductance through two quantum dots, which are connected in series to left and fight leads, is calculated by using the numerical renormalization group method. As the hopping between the dots increases from a very small value, the following states continuously appear: (i) Kondo singlet state of each dot with its adjacent-site lead, (ii) singlet state between the local spins on the dots, and (iii) double occupancy in the bonding orbital of the two dots. The conductance shows peaks at the crossover regions between these states. The peak at the boundary between (i) and (ii) especially has the unitarity limit value of 2e2/h because of coherent connection through the lead-dot-dot-lead. For the strongly correlated cases, the characteristic energy scale of the coherent peak shows anomalous decrease relating to the quantum critical transition known for the two-impurity Kondo effect. The two dot systems give a new realization of the two-impurity Kondo problem.

Original languageEnglish
Pages (from-to)10260-10267
Number of pages8
JournalPhysical Review B - Condensed Matter and Materials Physics
Issue number15
Publication statusPublished - 2000 Oct 15
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics


Dive into the research topics of 'Two-impurity kondo effect in double-quantum-dot systems: Effect of interdot kinetic exchange coupling'. Together they form a unique fingerprint.

Cite this