Quantum phases and phase transitions in multilayered dipolar excitons

TYPECondensed Matter Seminar
Speaker:Snir Gazit
Affiliation:HUJI
Organizer:Anna Keselman
Date:23.05.2023
Time:12:30 - 13:30
Location:Lidow Nathan Rosen (300)
Abstract:

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 excitons density, dipolar interactions destabilize the quadropolar state and nucleate a staggered dipolar phase with a 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.