title: Dispersive readout of a few-electron double quantum dot with fast RF gate sensors.
abstract: We report the dispersive charge-state readout of a double quantum dot in the few-electron regime using the in situ gate electrodes as sensitive detectors. We benchmark this gate sensing technique against the well established quantum point contact charge detector and find comparable performance with a bandwidth of ∼ 10 MHz and an equivalent charge sensitivity of ∼ 6.3 × 10(-3) e/sqrt[Hz]. Dispersive gate sensing alleviates the burden of separate charge detectors for quantum dot systems and promises to enable readout of qubits in scaled-up arrays.
authors.affiliation: ARC Centre of Excellence for Engineered Quantum Systems, School of Physics, The University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: J I
authors.initials: JI
authors.lastname: Colless
authors.affiliation: ARC Centre of Excellence for Engineered Quantum Systems, School of Physics, The University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: A C
authors.initials: AC
authors.lastname: Mahoney
authors.affiliation: ARC Centre of Excellence for Engineered Quantum Systems, School of Physics, The University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: J M
authors.initials: JM
authors.lastname: Hornibrook
authors.affiliation: ARC Centre of Excellence for Engineered Quantum Systems, School of Physics, The University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: A C
authors.initials: AC
authors.lastname: Doherty
authors.affiliation: Materials Department, University of California, Santa Barbara, California 93106, USA.
authors.forename: H
authors.initials: H
authors.lastname: Lu
authors.affiliation: Materials Department, University of California, Santa Barbara, California 93106, USA.
authors.forename: A C
authors.initials: AC
authors.lastname: Gossard
authors.affiliation: ARC Centre of Excellence for Engineered Quantum Systems, School of Physics, The University of Sydney, Sydney, New South Wales 2006, Australia.
authors.forename: D J
authors.initials: DJ
authors.lastname: Reilly