title: Undoped accumulation-mode Si/SiGe quantum dots.
abstract: We report on a quantum dot device design that combines the low disorder properties of undoped SiGe heterostructure materials with an overlapping gate stack in which each electrostatic gate has a dominant and unique function-control of individual quantum dot occupancies and of lateral tunneling into and between dots. Control of the tunneling rate between a dot and an electron bath is demonstrated over more than nine orders of magnitude and independently confirmed by direct measurement within the bandwidth of our amplifiers. The inter-dot tunnel coupling at the [Formula: see text] charge configuration anti-crossing is directly measured to quantify the control of a single inter-dot tunnel barrier gate. A simple exponential dependence is sufficient to describe each of these tunneling processes as a function of the controlling gate voltage.
authors: HRL Laboratories, LLC, Malibu, CA 90265, USA.
authors: M G
authors: MG
authors: Borselli
authors: K
authors: K
authors: Eng
authors: R S
authors: RS
authors: Ross
authors: T M
authors: TM
authors: Hazard
authors: K S
authors: KS
authors: Holabird
authors: B
authors: B
authors: Huang
authors: A A
authors: AA
authors: Kiselev
authors: P W
authors: PW
authors: Deelman
authors: L D
authors: LD
authors: Warren
authors: I
authors: I
authors: Milosavljevic
authors: A E
authors: AE
authors: Schmitz
authors: M
authors: M
authors: Sokolich
authors: M F
authors: MF
authors: Gyure
authors: A T
authors: AT
authors: Hunter