Quantum Phases and Phase Transitions in Multilayered Dipolar Excitons

Dipolar excitons in semiconductors and transition metal dichalcogenide (TMD) heterostructures have recently emerged as a promising experimental platform for realizing strongly correlated quantum many-body phenomena. In my talk, I will discuss multilayered structures that expose the anisotropic nature of dipolar interactions. Specifically, I will present a trilayer system that allows stabilizing a quantum quadrupolar state via tunneling events of holes between outer layers, as was recently observed experimentally. With increased exciton density, dipolar interactions destabilize the quadrupolar state and nucleate a staggered dipolar phase with broken layer symmetry. Furthermore, I will show that quadrilayer structures can support an interlayer molecular ("pair") superfluid phase and argue that it can be experimentally detected via a jump discontinuity in the exciton spectral shifts. Lastly, tuning exciton densities drives a quantum phase transition belonging to the (2+1)D XY universality class, marked by breaking interlayer molecules and softening of the associated binding energy. If time permits, I'll present recent unpublished results indicating a trimer condensate in antiparallel dipolar bilayers.