Single-Carrier Transport in Graphene/hBN Superlattices

Abstract

Graphene/hexagonal boron nitride (hBN) moiré superlattices have attracted interest for use in the study of many-body effects and fractal physics in Dirac fermion systems. Many exotic transport properties have been intensively examined in such superlattices, but previous studies have not focused on single-carrier transport. The investigation of the single-carrier behavior in these superlattices would lead to an understanding of the transition of singleparticle/correlated phenomena. Here, we show the single-carrier transport in a high-quality bilayer graphene/hBN superlattice-based quantum dot device. We demonstrate remarkable device controllability in the energy range near the charge neutrality point (CNP) and the hole-side satellite point. Under a perpendicular magnetic field, Coulomb oscillations disappear near the CNP, which could be a signature of the crossover between Coulomb blockade and quantum Hall regimes. Our results pave the way for exploring the relationship of single-electron transport and fractal quantum Hall effects with correlated phenomena in two-dimensional quantum materials.

Developing Graphene‐Based Moiré Heterostructures for Twistronics

“…Reproduced with permission. [ 121 ] Copyright 2020, American Chemical Society. d) Schematic illustration of three different moiré superlattices formed in the h ‐BN/graphene/ h ‐BN heterostructure.…”

“…In addition to the above‐mentioned moiré heterostructures composed of MLG and h ‐BN, there are other graphene/ h ‐BN heterostructures, such as BLG/ h ‐BN, [ 121 ] TLG/ h ‐BN, [ 125 ] and h ‐BN/graphene/ h ‐BN. [ 122 ] The moiré pattern of the BLG/ h ‐BN heterostructures with wavelength λ and twist angle θ illustrated the alignment between graphene and h ‐BN (Figure 8c ).…”

“…c) Schematic illustration of the BLG/h-BN superlattice. Reproduced with permission [121]. Copyright 2020, American Chemical Society.…”

Two‐Dimensional Metal Chalcogenide Heterostructures: Designed Growth and Emerging Novel Applications

“…[ 18,46–52 ] Furthermore, superlattices have also gained much attention, including moiré superlattices and multiheterostructures. [ 53–85 ] Among them, 2D metal chalcogenides represent a class of ideal materials for the synthesis of 2D heterostructures due to their tunable bandgap from semiconductors to topological insulators, strong light–matter interactions, [ 64,65 ] and multifunctional structures via artificial construction. [ 86–89 ]…”

Fermi Velocity Modulation Induced Low‐Bias Negative Differential Resistance in Graphene Double Barrier Resonant Tunneling diode

“…[ 1,4 ] In this regard, several reports demonstrated how the Fermi velocity alters graphene transport features [ 11–14 ] and its device performance. [ 15,16 ] Among graphene morphologies, quantum wells (QWs), [ 17,18 ] hetrostructures, [ 19–22 ] and superlattices (SLs) [ 23–26 ] have widely been implemented in designing/fabrication emerging devices [ 27–29 ] and exploring novel phenomenon [ 30–35 ] beyond the reach of exciting materials. In this context, resonant tunneling as one of the unique transport processes in SLs exhibited great promise to enrich the potential of SLs and QW devices including tunnel transistors (TFETs) [ 36–38 ] and resonant tunneling diodes (RTDs).…”