Excitons in the fractional quantum Hall effect

Professor Jia Leo Li

Brown University

An exciton is a Coulomb-driven bound state, typically formed by an electron and a hole. However, under the influence of charge fractionalization, a more exotic construction of exciton can emerge from the pairing between fractional particle and hole charges, leading to intriguing new physical phenomena. In this talk, I will discuss key transport signatures of excitonic pairing that coexist with the fractional quantum Hall effect in a quantum Hall graphene bilayer. This coexistence unveils a novel construction of the fractional quantum Hall effect, where exciton pairing plays a crucial role in defining the underlying wavefunction. By exploring the two-dimensional phase space defined by Landau-level filling and layer imbalance, we identify distinct exciton compositions, including those where pairing involves fractional charge constituents.