Local Manipulation of Quantum Hall States

The electron cyclotron orbits in 2D materials are quantized into highly-degenerate Landau levels under a strong magnetic field, leading to dissipationless longitudinal transport and quantized transverse conductance, known as the quantum Hall (QH) effect. Of particular interest are those driven by strong electron-electron interactions, such as QH states with broken symmetry, fractional fillings, and small energy scales. Utilizing gate-defined nanostructures, we electrostatically and locally manipulate the emergence, evolution, hybridization, and transmission of QH edge states, and selectively probe them with high spatial and energy resolution, towards understanding the rich underlying physics and novel device functionalities.

Selective Manipulation and Tunneling Spectroscopy of Broken-symmetry Quantum Hall States in a Hybrid-edge Quantum Point Contact 

Demonstrate improved electrostatic control over the separation, position, and coupling of each broken-symmetry compressible strip in graphene via a hybrid-edge and dual-gated quantum point contact.

Wei Ren*, Xi Zhang*, Jaden Ma, Xihe Han, Kenji Watanabe, Takashi Taniguchi, Ke Wang, Phys. Rev. B 110, 245423 (2023) 
 

 

Tunneling Spectroscopy of Quantum Hall Edge States in Gate-defined Bilayer Graphene PN Networks 

Report tunneling transport in spatially controlled networks of quantum Hall (QH) edge states in bilayer graphene via gate-defined electrostatics.

K. Wang, A. Harzheim, T. Taniguchi, K. Watanabe, P. Kim, Phys. Rev. Lett. 122, 146801, (2019)