Topological Quantum Device

Flat Bands & Correlated Topological Physics

Integer/Fractional Quantum Hall & Quantum Anomalous Hall Effect
Integer/Fractional Chern Insulators & Anomalous Hall Crystals
Topological Superconductivity & Symmetry-Broken Correlated States

Flat electronic bands quench the kinetic energy and let Coulomb interactions dominate, driving a wealth of correlated and topologically nontrivial ground states. When such bands carry a finite Chern number, interactions can stabilize quantized Hall responses even at zero magnetic field — bridging the physics of the conventional integer and fractional quantum Hall effects with their anomalous, field-free counterparts.

Recent advances in van der Waals heterostructures have brought this regime within reach. Moiré superlattices and, more recently, moiré-free rhombohedral multilayer graphene host displacement-field-tunable flat bands in which fractional quantum anomalous Hall states, anomalous Hall crystals, and gate-tunable superconductivity have all been observed. These platforms place strong correlations and band topology on an equal footing, opening routes toward intertwined orders and hybrid superconductor–topological interfaces. Our ongoing research focuses on discovering and controlling these fragile correlated ground states across diverse 2D materials.

Gate-Defined Quantum Dots

Electrostatic Confinement in Bilayer Graphene and TMDCs
Few-/Single-Electron Regime: Coulomb Blockade and Charge Sensing
Spin–Valley Qubits with Pauli-Blockade Readout

Gate-defined quantum dots confine individual charge carriers using purely electrostatic potentials, without etching the host material. In bilayer graphene a perpendicular displacement field opens a tunable band gap, while TMDCs such as MoS₂ and WSe₂ provide an intrinsic gap for direct confinement. Relying on smooth potentials rather than physical edges suppresses edge disorder, yielding clean, reproducible devices.

A global gate sets the gap or accumulates carriers, while patterned split gates shape the confinement potential and tunnel barriers, driving the dot down to the few- and single-electron regime probed by transport or dispersive charge sensing.

Both platforms host a rich spin–valley level structure with Pauli blockade for single-shot readout: bilayer graphene offers weak spin–orbit coupling and a nuclear-spin-free ¹²C lattice for long coherence, while TMDCs provide strong spin–orbit coupling and spin–valley locking. Coupling dots into arrays with fast RF reflectometry readout points toward scalable spin–valley qubit architectures.