*ITAMP Lunch Seminar* *Speaker:* Dominik Wild (Harvard University) *Date:* Thursday, April 12th *Time:* 12:00-1:00 pm Includes Pizza. *Title: Few- and Many-Body Quantum Mechanics in 2D Semiconductors* *Abstract: Atomically thin semiconductors such as monolayers of transition metal dichalcogenides (TMDs) are promising candidates for applications in quantum optics and the study of many-body dynamics. In the first part of the talk, I show that TMDs are excellent reflectors close to an exciton resonance. A TMD monolayer thus forms an optical resonator when placed in front of a conventional mirror, which can be exploited to enhance quantum nonlinearities of the TMD. In the second part, I discuss polarons formed by excitons interacting with a Fermi sea of electrons, highlighting key differences from polarons in ultracold gases. In particular, I demonstrate that the polaron dispersion in TMDs develops a roton-like minimum at finite momentum due to Pauli blocking, which may account for experimentally observed discrepancies between absorption and photoluminescence spectra.* *Location: *B-106 @ Center for Astrophysics (60 Garden Street) *Directions: *After entering the lobby of the CfA, turn right to enter the hallway of the B building. In the hallway, turn right again, B-106 will be at the end of the hallway on the left side.