Electronic Steady States of Laser-Driven Moire Materials
Christopher Yang, California Institute of Technology
The electrical transport properties of periodically driven (e.g., laser-driven) materials can encode information about the electronic properties (e.g., bandstructure), drive-induced topology, electron-phonon interactions, and electron-electron interactions within the system.2, 3 In this presentation, we will consider both THz and UV frequency laser-driven twisted bilayer graphene (TBG) at low temperatures. We will discuss how resulting experimental observables of the driven system can probe the electronic properties of the material. For instance, the optically-induced topological bandstructure makes it possible to observe an anomalous quantum Hall effect in the system, whose conductivity reveals the kinematic interplay between electrons and phonons in the system. We demonstrate that the THz laser drive flattens the effective bandstructure of TB, and the resulting anomalous transport properties behave differently in the weak drive and strong drive regimes when electrons are faster and slower than phonons, respectively.4 We will lastly show that interacting, Floquet TBG can avoid overheating by dissipating the laser drive energy to its low-temperature bath of phonons.1
References:1C. Yang, I. Esin, C. Lewandowski, and G. Refael, Optical Control of Slow Topological Electrons in Moire Systems, arXiv:2301.02248 (2023).
2K. I. Seetharam, C. E. Bardyn, N. H. Linder, M. S. Rudner, and G. Refael, Steady states of interaction Floquet insulators, Physical Review B 99, 10.1103/PhysRevB.99.014307 (2019).
3N. H. Linder, G. Refael, and V. Galitski, Floquet topological insulator in semiconductor quantum wells, Nature Physics 7, 10.1038/nphys1926 (2011).
4O. Katz, G. Refael, and N. H. Linder, Optically induced flat bands in twisted bilayer graphene, Physical Review B 102, 10.1103/PhysRevB.102.155123 (2020).
Abstract Author(s): Christopher Yang, Iliya Esin, Cyprian Lewandowski, Gil Refael