Physics Department Colloquium: Tuesday, January 21st, 2020 - Moiré Excitons in 2D Semiconducting Superlattices

Event Date: 

Tuesday, January 21, 2020 - 3:45pm

Event Date Details: 

Refreshments served at 3:30pm

Event Location: 

  • Broida 1640
  • Physics Department Colloquium

The moiré superlattice formed between two-dimensional (2D) materials provides a powerful tool to engineer novel quantum phenomena. The most striking phenomena emerge in the “strong-coupling” regime, where the periodic moiré potential dominates over the relevant kinetic energy and qualitatively changes the quasiparticle behaviors in both real and momentum space. Electrons in the “strong-coupling” regime have shown intriguing phenomena. However, a similar opportunity to engineer bosonic phases has not been experimentally explored. In this talk, I will show the emergence of intra- and inter-layer moiré excitons, i.e. bosons composed of tightly-bound electron-hole pairs, in WSe2/WS2 superlattices in the “strong-coupling” regime. The strong moiré potential trapped excitons into a periodic boson lattice in the real space, exhibiting exotic behaviors. I will also discuss strongly correlated electron phases emerging in this platform.

Chenhao Jin, Kavli Institute at Cornell for Nanoscale Science