Ground state of the parallel double quantum dot system

Rok Žitko, Jernej Mravlje, Kristjan Haule

Research output: Contribution to journalArticlepeer-review

22 Scopus citations


We resolve the controversy regarding the ground state of the parallel double quantum dot system near half filling. The numerical renormalization group predicts an underscreened Kondo state with residual spin-1/2 magnetic moment, ln 2 residual impurity entropy, and unitary conductance, while the Bethe ansatz solution predicts a fully screened impurity, regular Fermi-liquid ground state, and zero conductance. We calculate the impurity entropy of the system as a function of the temperature using the hybridization-expansion continuous-time quantum Monte Carlo technique, which is a numerically exact stochastic method, and find excellent agreement with the numerical renormalization group results. We show that the origin of the unconventional behavior in this model is the odd-symmetry "dark state" on the dots.

Original languageEnglish (US)
Article number066602
JournalPhysical review letters
Issue number6
StatePublished - Feb 8 2012

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)


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