Undoped accumulation-mode Si/SiGe quantum dots. (25th August 2015)

• Record Type: Journal Article
• Authors: Borselli, M G; Eng, K; Ross, R S; Hazard, T M; Holabird, K S; Huang, B; Kiselev, A A; Deelman, P W; Warren, L D; Milosavljevic, I; Schmitz, A E; Sokolich, M; Gyure, M F; Hunter, A T
• Is Part Of: Nanotechnology. Volume 26:Number 37(2015)
• Publication Date: 2015-08-25
• Subjects: quantum dots -- SiGe heterostructures -- Si qubits; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/0957-4484/26/37/375202
• Languages: English
• ISSNs: 0957-4484

Abstract

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 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.