title: Quantitative estimation of exchange interaction energy using two-electron vertical double quantum dots.
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 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-T transition energy or J is compensated by the Zeeman energy. We use this feature to derive J depending on Delta between the S-S and T-T resonances. The obtained J versus Delta including the resonance effect is perfectly reproduced by Hubbard model calculations.
authors.affiliation: Institute for Nano Quantum Information Electronics, the University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan. kodera@iis.u-tokyo.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Kodera
authors.forename: K
authors.initials: K
authors.lastname: Ono
authors.forename: Y
authors.initials: Y
authors.lastname: Kitamura
authors.forename: Y
authors.initials: Y
authors.lastname: Tokura
authors.forename: Y
authors.initials: Y
authors.lastname: Arakawa
authors.forename: S
authors.initials: S
authors.lastname: Tarucha