Berlin 2024 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
HL: Fachverband Halbleiterphysik
HL 9: 2D Materials and Heterostructures: Interlayer Excitons
HL 9.5: Talk
Monday, March 18, 2024, 16:00–16:15, EW 201
Impact of hybrid exciton-exciton interactions on transport in 2D materials — •Daniel Erkensten1, Samuel Brem2, Raul Perea-Causin1, Joakim Hagel1, Fedele Tagarelli3, Edoardo Lopriore3, Ermin Malic2,1, and Andras Kis3 — 1Chalmers University of Technology — 2Philipps-Universität Marburg — 3Ecole Polytechnique Fédérale de Lausanne
Transition-metal dichalcogenide bilayers host exciton states that hybridize via electron or hole tunneling, forming layer-hybridized excitons with large oscillator strengths and out-of-plane dipole moments. In this joint theory-experiment work, we combine microscopic many-particle theory with spatiotemporal measurements to investigate the role of hybrid exciton-exciton interactions in exciton transport in WSe2 homobilayers [1,2]. The energetically lowest state in these structures is shown to be electrically tunable, transitioning from an intralayer-like to an interlayer-like ground state via the application of an out-of-plane electric field [1]. This finding leads to two intriguing interaction regimes for hybrid excitons: a low-dipole regime at small electric fields involving weakly interacting excitons which exhibit conventional diffusion, and a high-dipole regime at elevated electric fields governed by strongly interacting excitons and highly anomalous diffusion. Our work highlights the remarkable electrical tunability of hybrid exciton-exciton interactions, providing insights for future research in this evolving field.
[1] D.Erkensten et al. Nanoscale, 15, 11064-11071 (2023).
[2] F. Tagarelli, D. Erkensten et al. Nat. Photonics, 71,
615-621 (2023).
Keywords: excitons; transition-metal dichalcogenides