title: A Noninvasive Method for Nanoscale Electrostatic Gating of Pristine Materials.
abstract: Electrostatic gating is essential for defining and control of semiconducting devices. However, nanofabrication processes required for depositing gates inevitably degrade the pristine quality of the material of interest. Examples of materials that suffer from such degradation include ultrahigh mobility GaAs/AlGaAs two-dimensional electron gases (2DEGs), graphene, topological insulators, and nanowires. To preserve the pristine material properties, we have developed a flip-chip setup where gates are separated from the material by a vacuum, which allows nanoscale electrostatic gating of the material without exposing it to invasive nanoprocessing. An additional benefit is the vacuum between gates and material, which, unlike gate dielectrics, is free from charge traps. We demonstrate the operation and feasibility of the flip-chip setup by achieving quantum interference at integer quantum Hall states in a Fabry-Pérot interferometer based on a GaAs/AlGaAs 2DEG. Our results pave the way for the study of exotic phenomena including fragile fractional quantum Hall states by preserving the high quality of the material.
authors.affiliation: QuTech and Kavli Institute of Nanoscience, Delft University of Technology , GA 2600 Delft, The Netherlands.
authors.forename: Arjan J A
authors.initials: AJ
authors.lastname: Beukman
authors.affiliation: QuTech and Kavli Institute of Nanoscience, Delft University of Technology , GA 2600 Delft, The Netherlands.
authors.forename: Fanming
authors.initials: F
authors.lastname: Qu
authors.affiliation: Department of Electrical Engineering, Princeton University , Princeton, New Jersey 08544, United States.
authors.forename: Ken W
authors.initials: KW
authors.lastname: West
authors.affiliation: Department of Electrical Engineering, Princeton University , Princeton, New Jersey 08544, United States.
authors.forename: Loren N
authors.initials: LN
authors.lastname: Pfeiffer
authors.affiliation: QuTech and Kavli Institute of Nanoscience, Delft University of Technology , GA 2600 Delft, The Netherlands.
authors.forename: Leo P
authors.initials: LP
authors.lastname: Kouwenhoven
keywords: Fabry-Pérot interferometer; Nanoscale gating; Quantum Hall effect; flip-chip; noninvasive