Quantum Cafe Webinar: Jie Shan

Topic: Strongly correlated excitonic insulator in atomic double layers

Abstract: Excitonic insulators (EI) arise from the formation of bound electron-hole pairs (excitons) in semiconductors and provide a solid-state platform for quantum many-boson physics. Although the concept of EI has been understood for sixty years, it has been challenging to establish distinct experimental signatures of its realization. One problem is that exciton coherence in condensed phases inevitably couples to the crystal Hamiltonian (disordered or not) so that condensation does not imply superfluidity. A second problem is that the exciton population of a particular material depends very sensitively on band structure details and cannot be controlled. In this talk, I discuss a recent experiment in which we solve both problems by establishing electrical control of the chemical potentials of interlayer excitons in semiconducting transition metal dichalcogenide double layers and probing the thermodynamic properties of exciton fluids by capacitance measurements. I will also discuss the possibility of creating exciton fluids in a lattice to realize the Bose-Hubbard model.

For Zoom details please contact Mary Kate Hennelly at [email protected]