Many-body correlated phenomena in 1D and 2D quantum materials

Light-matter interaction has been demonstrated to provide an excellent platform for studying many-body effects in a wide variety of quantum materials, ranging from perovskites [1] to Moiré interfaces [2,3]. In this talk, I will first present how the SrTiO3 phonon-polariton in the THz frequency range [4,5] manifests itself in the electronic compressibility when used as a dielectric in a parallel plate capacitor. I will compare its capacitive signatures in graphene and 2DEG electrodes, and discuss the role of interlayer electron-electron interactions [6]. Secondly, I will present novel correlated phases probed via STM measurements in quasi-one-dimensional rhombohedral graphene channels formed when a marginally twisted monolayer on bilayer graphene is strained beyond the critical point at which its triangular symmetry is broken [7].

[1] Li, Xian, et al. "Terahertz field–induced ferroelectricity in quantum paraelectric SrTiO3." Science 364.6445 (2019): 1079-1082.
[2] Krishna Kumar, R., Li, G., Bertini, R. et al. Terahertz photocurrent probe of quantum geometry and interactions in magic-angle twisted bilayer graphene. Nat. Mater. (2025).
[3] Wilson, Nathan P., et al. "Excitons and emergent quantum phenomena in stacked 2D semiconductors." Nature 599.7885 (2021): 383-392.
[4] M. Fechner, M. Först, G. Orenstein, V. Krapivin, A. Disa, M. Buzzi, A. von Hoegen, G. de la Pena, Q. L. Nguyen, R. Mankowsky, M. Sander, H. Lemke, Y. Deng, M. Trigo, A. Cavalleri “Quenched lattice fluctuations in optically driven SrTiO3 “ Nature Materials 23 (3), 363–368 (2024)
[5] Li, Wei, et al. "A Hidden Quantum Paraelectric Phase in SrTiO3 Induced by Terahertz Field." arXiv preprint, arXiv:2412.20887 (2024).
[6] Berthod, Christophe, et al. "Theory of cross quantum capacitance." Physical Review Research 3.4 (2021): 043036.
[7] Lebedeva, Irina V., and Andrey M. Popov. "Two phases with different domain wall networks and a reentrant phase transition in bilayer graphene under strain." Physical Review Letters 124.11 (2020): 116101.

If you would like to meet with Adrin during his visit, please contact Analyn Almeida.