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Physical Review Letters

Quantitative Estimation of Exchange Interaction Energy Using Two-Electron Vertical Double Quantum Dots

Tetsuo Kodera, Keiji Ono, Y. Kitamura, 康弘 都倉, Yasuhiko Arakawa, Seigo Tarucha

Published Apr 8, 2009• 25 citations
Publisher

Abstract

We use Pauli-spin blockade in two-electron vertical double quantum dots to quantitatively estimate the exchange energy $J$ in a wide range of interdot level detuning $\ensuremath{\Delta}$ and fully compare it with calculations. Pauli-spin blockade is lifted via a singlet- ($S$-)triplet ($T$) transition mediated by hyperfine coupling, which abruptly occurs in our devices when the $S\mathrm{\text{\ensuremath{-}}}T$ transition energy or $J$ is compensated by the Zeeman energy. We use this feature to derive $J$ depending on $\ensuremath{\Delta}$ between the $S\mathrm{\text{\ensuremath{-}}}S$ and $T\mathrm{\text{\ensuremath{-}}}T$ resonances. The obtained $J$ versus $\ensuremath{\Delta}$ including the resonance effect is perfectly reproduced by Hubbard model calculations.

DOI
10.1103/physrevlett.102.146802

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