title: Phonon-mediated back-action of a charge readout on a double quantum dot.
abstract: Quantum point contacts are in use as an on-chip capacitative readout for the charge state of quantum dot systems. Here we investigate experimentally the back-action of quantum point contacts (QPCs) on a nearby double quantum dot (DQD). Driving current through a QPC influences the DQD state and leads to a measurable current flow in the DQD circuit with no bias voltage applied. The responsible mechanism is an indirect back-action process due to ohmic heating of the phonon bath. The system behaves like a thermoelectric engine, where a temperature gradient between the phonon bath and the electronic bath generates work observable as a measurable current flowing through the DQD.
authors.affiliation: Solid State Physics Laboratory, ETH Zurich, CH-8093 Zurich, Switzerland. szerer@phys.ethz.ch
authors.forename: U
authors.initials: U
authors.lastname: Gasser
authors.forename: S
authors.initials: S
authors.lastname: Gustavsson
authors.forename: B
authors.initials: B
authors.lastname: Küng
authors.forename: K
authors.initials: K
authors.lastname: Ensslin
authors.forename: T
authors.initials: T
authors.lastname: Ihn