High-Temperature Quantum Hall Effect in Graphite-Gated Graphene Heterostructure Devices with High Carrier Mobility

• Published in: Nanomaterials (Basel, Switzerland) Vol. 12; no. 21; p. 3777
• Main Authors: Zhou, Siyu, Zhu, Mengjian, Liu, Qiang, Xiao, Yang, Cui, Ziru, Guo, Chucai
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 26-10-2022; MDPI
• Subjects: Boron; Boron nitride; Carrier mobility; Chemical vapor deposition; Condensed matter physics; Devices; Electromagnetism; Electron gas; Fermions; field-effect devices; Graphene; Graphite; hBN; heterostructure; Heterostructures; High temperature; Integers; Low temperature; Magnetic fields; Mobility; Plateaus; Quantum Hall effect; Room temperature; Series (mathematics); Silicon dioxide; Silicon substrates; carrier mobility; field-effect devices; Graphene; hBN; heterostructure; quantum Hall effect
• ISSN: 2079-4991; 2079-4991
• DOI: 10.3390/nano12213777

Since the discovery of the quantum Hall effect in 1980, it has attracted intense interest in condensed matter physics and has led to a new type of metrological standard by utilizing the resistance quantum. Graphene, a true two-dimensional electron gas material, has demonstrated the half-integer quantum Hall effect and composite-fermion fractional quantum Hall effect due to its unique massless Dirac fermions and ultra-high carrier mobility. Here, we use a monolayer graphene encapsulated with hexagonal boron nitride and few-layer graphite to fabricate micrometer-scale graphene Hall devices. The application of a graphite gate electrode significantly screens the phonon scattering from a conventional SiO
/Si substrate, and thus enhances the carrier mobility of graphene. At a low temperature, the carrier mobility of graphene devices can reach 3 × 10
cm
/V·s, and at room temperature, the carrier mobility can still exceed 1 × 10
cm
/V·s, which is very helpful for the development of high-temperature quantum Hall effects under moderate magnetic fields. At a low temperature of 1.6 K, a series of half-integer quantum Hall plateaus are well-observed in graphene with a magnetic field of 1 T. More importantly, the
= ±2 quantum Hall plateau clearly persists up to 150 K with only a few-tesla magnetic field. These findings show that graphite-gated high-mobility graphene devices hold great potential for high-sensitivity Hall sensors and resistance metrology standards for the new Système International d'unités.