Speaker
Description
Electrostatic control is central to the operation of semiconductor
junctions, but its interplay with band topology remains largely
unexplored. We investigate lateral junctions between two-dimensional
insulating phases with different Chern numbers in a perpendicular
magnetic field. From the electrostatic point of view, the spectral asymmetry of the Chern insulator acts as an intrinsic effective dopant density fixed by topology and tunable by the magnetic field. As a consequence, two regions with different Chern numbers acquire different chemical potentials at charge neutrality, thereby generating an intrinsic built-in potential across the junction. We derive this built-in potential analytically and solve the two-dimensional Poisson equation
self-consistently to obtain the associated charge and potential
profiles. Our results show that Chern-number mismatch can affect
electrostatic equilibrium in two-dimensional junctions, providing a
route to probe topological spectral asymmetry through electrostatic
observables such as junction capacitance.