title: Large nuclear overhauser fields detected in vertically coupled double quantum dots.
abstract: We report the electrical induction and detection of dynamic nuclear polarization in the spin-blockade regime of double GaAs vertical quantum dots. The nuclear Overhauser field measurement relies on bias voltage control of the interdot spin exchange coupling and measurement of dc current at variable external magnetic fields. The largest Overhauser field observed was about 4 T, corresponding to a nuclear polarization approximately 40% for the electronic g factor typical of these devices, |g*| approximately 0.25. A phenomenological model is proposed to explain these observations.
authors.affiliation: Institute for Quantum Computing, University of Waterloo, 200 University Ave. W., Waterloo, ON, N2L 3G1, Canada.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Baugh
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Kitamura
authors.forename: Keiji
authors.initials: K
authors.lastname: Ono
authors.forename: Seigo
authors.initials: S
authors.lastname: Tarucha