High quality electrostatically defined hall bars in monolayer graphene

Abstract

Realizing graphene's promise as an atomically thin and tunable platform for fundamental studies and future applications in quantum transport requires the ability to electrostatically define the geometry of the structure and control the carrier concentration, without compromising the quality of the system. Here, we demonstrate the working principle of a new generation of high quality gate defined graphene samples, where the challenge of doing so in a gapless semiconductor is overcome by using the $\nu =0$ insulating state, which emerges at modest applied magnetic fields. In order to verify that the quality of our devices is not compromised by the presence of multiple gates we compare the electronic transport response of different sample geometries, paying close attention to fragile quantum states, such as the fractional quantum Hall (FQH) states, that are highly susceptible to disorder. The ability to define local depletion regions without compromising device quality establishes a new approach towards structuring graphene-based quantum transport devices.

References in corpus (7)

• The electronic properties of graphene
• Multicomponent fractional quantum Hall effect in graphene
• Tunable Fractional Quantum Hall Phases in Bilayer Graphene
• Composite Fermions and Broken Symmetries in Graphene
• Gate-Defined Graphene Quantum Point Contact in the Quantum Hall Regime
• Non-Equilibrated Counter Propagating Edge Modes in the Fractional Quantum Hall Regime
• Direct Measurement of the g-Factor of Composite Fermions