Bumseop Kim

Ulsan National Institute of Science and Technology (UNIST), Korea

30 January 2024 Tue 4 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                     

The interaction between light and matter not only plays a crucial role in our life but also holds tremendous potential for applications in condensed matter physics. Harnessing light through phenomena such as the photovoltaic effect enables the generation of electricity, while utilizing various polarized lights allows for the detection and even manipulation of material states [1-3]. Understanding the interaction between light and matter is indispensable as it directly correlates with the properties of materials. However, unraveling the behavior of electrons induced by light in interacting many-body Hamiltonians poses significant computational challenges.

In this presentation, we delve into two intriguing light-driven phenomena using real-time time-dependent density functional theory [4, 5]. The first explores the giant bulk photovoltaic effect in WS2 nanotubes, while the second investigates the optoelectronic manifestation of orbital angular momentum in helical Se chains. Despite the approximation of density functional theory in the limit of a non-interacting one-body Hamiltonian, our results not only align well with experimental findings but also elucidate the origin of these properties. Our research contributes by providing a tool to study light-induced properties using the simplest approximations, thus offering impactful insights into the field.

[1] Xu, SY. et al. Electrically switchable Berry curvature dipole in the monolayer topological insulator WTe2. Nat. Phys. 14, 900–906 (2018)

[2] Mitrano, M. et al. Possible light-induced superconductivity in K3C60 at high temperature. Nature 530, 461–464 (2016)

[3] Li, X. et al. Terahertz field–induced ferroelectricity in quantum paraelectric SrTiO3. Science 364, 1079 (2019)

[4] Kim, B., Park, N. & Kim, J. Giant bulk photovoltaic effect driven by the wall-to-wall charge shift in WS2 nanotubes. Nat. Commun. 13, 3237 (2022).

[5] Kim, B. et al. Optoelectronic Manifestation of Orbital Angular Momentum Driven by Chiral Hopping in Helical Se Chains. ACS Nano 17, 18873-18882 (2023).

  1. exploring light-induced phenomena in condensed matter physics within the framework of density-functional theory