Emergent Quantum Phenomena in Rhombohedral Graphene
Name
han-tonghang-phd-physics-2026-thesis.pdf
Size
21.25 MB
Format
Adobe PDF
Checksum (MD5)
1ff0bffe7a25f186c647adce13fc773b
Author(s)
Han, Tonghang
Advisor(s)
Ju, Long
Date Issued
May 2026
Publisher
Massachusetts Institute of Technology
Abstract
Rhombohedral multilayer graphene has emerged as a highly tunable platform for studying quantum phases arising from strong electron correlations and band topology. Its low-energy bands become increasingly flat with layer number and carry a large valley Berry phase. Dual electrostatic gating provides independent in situ control of carrier density and perpendicular displacement field, enabling continuous tuning of the bandwidth, layer polarization, and Berry-curvature distribution. Further control is obtained by crystallographic alignment with hexagonal boron nitride, which generates moiré superlattices, or by proximity coupling to transition metal dichalcogenides, which enhances spin–orbit interactions. This thesis reports a broad set of correlated and topological phases in dual-gated rhombohedral graphene devices. These include isospin-polarized metals, an orbital multiferroic state, Wigner-crystal and metallic Wigner-crystal phases, chiral superconductivity, a layer antiferromagnet at charge neutrality, a Chern-number-five quantum anomalous Hall state, and fractional quantum anomalous Hall states. These results include several experimentally unprecedented phases and demonstrate that rhombohedral multilayer graphene offers a versatile route to engineering new phases of matter and point toward future opportunities including tunable topological electronics and quantum information technologies.
MIT Department
Massachusetts Institute of Technology. Department of Physics
Terms of Use
In Copyright - Educational Use Permitted
Copyright retained by author(s)
Persistent DSpace Link
