Dogyun Ko

PCS IBS (PhD thesis Defense)

1 Jun 2023 Thu 1.40 pm

                                      IBS Center for Theoretical Physics of Complex Systems (PCS), Administrative Office (B349), Theory Wing, 3rd floor

                                      Expo-ro 55, Yuseong-gu, Daejeon, South Korea, 34126 Tel: +82-42-878-8633                     

We study the formation and propagation of exciton-polariton condensates in different microcavities in the strong coupling regime. In the first part of the talk, we take a system of exciton-polaritons in a Kagome lattice and show that an initially localized condensate propagates in a specific direction in space in the presence of anisotropy in the lattice, and the initially localized condensate experiences revivals. We also study the formation of exciton-polariton condensates in two different lowest energy states at an exciton-polariton microcavity and the transition from the higher energy state to the ground state under pulsed and continuous wave excitation conditions by using various pump profiles. In the second part of the talk, we study the valley selection rules for the optical transitions from impurity states to the conduction band in two-dimensional Dirac materials, taking a monolayer of MoS2 as an example, we focus on the weak light-matter coupling regime. We find the spectrum of the light absorption coefficients and calculate the photon-drag electric current density due to the impurity-band transitions.

  1. polariton condensates & valleytronics