Single-electron transport in graphene-like nanostructures

Abstract

Two-dimensional (2D) materials for their versatile band structures and strictly 2D nature have attracted considerable attention over the past decade. Graphene is a robust material for spintronics owing to its weak spin-orbit and hyperfine interactions, while monolayer transition metal dichalcogenides (TMDs) possess a Zeeman effect-like band splitting in which the spin and valley degrees of freedom are nondegenerate. The surface states of topological insulators (TIs) exhibit a spinmomentum locking that opens up the possibility of controlling the spin degree of freedom in the absence of an external magnetic field. Nanostructures made of these materials are also viable for use in quantum computing applications involving the superposition and entanglement of individual charge and spin quanta. In this article, we review a selection of transport studies addressing the confinement and manipulation of charges in nanostructures fabricated from various 2D materials. We supply the entry-level knowledge for this field by first introducing the fundamental properties of 2D bulk materials followed by the theoretical background relevant to the physics of nanostructures. Subsequently, a historical review of experimental development in this field is presented, from the early demonstration of graphene nanodevices on SiO2 substrate to more recent progress in utilizing hexagonal boron nitride to reduce substrate disorder. In the second part of this article, we extend our discussion to TMDs and TI nanostructures. We aim to outline the current challenges and suggest how future work will be geared towards developing spin qubits in 2D materials.

Electrotunable artificial molecules based on van der Waals heterostructures

“…Previous quantum dots in 2D materials were widely studied in graphene ( 4 ), usually through the plasma etching methods ( 52 ), which introduces impurities and defects at the etched edge, leading to a limited controllability ( 53 ) and an enhanced noise level ( 54 ), thus limiting the performance of the quantum dot. Semiconducting MoS 2 makes it possible to achieve quantum dots via an electric field.…”

Scattering in graphene quantum dots under generalized uncertainty principle

“…60 It has extensively attracted attentions due to the new and strange properties that originated from the Dirac nature of the fermions in graphene. 61 One of the most interesting aspects of graphene is that it provides an unexpected bridge between condensed matter physics and high energy physics [62][63][64][65][66][67][68] and gives us the opportunity to study high energy phenomena through table top experiments. 69,70 Therefore, the GUP effect may be understood in future graphene scattering experiments.…”

Advances in Functional Nanomaterials Science

“…[250,251] Additionally, single-electron transport in graphene-like nanostructures was investigated and with it the current challenges to develop spin qubits and transport in 2D materials were outlined. [252] Similarly, He Zhu (Hangzhou Dianzi University) and coworkers demonstrated improved photodetectors based on functionalized semiconductor materials. Since IR and THz detection technology gained further importance in various fields due to the unique advantages of those techniques, blocked-impurity-band (BIB) THz photodetectors were developed in the past decades.…”