Professor Salvador Barraza-Lopez
University of Arkansas
Ferroelectricity, magnetoelasticity, structural phase transformations, topology, and non-linear optics of 2D materials
Location: 1080 Physics Research Building
Faculty Host: Jeanie Lau
Abstract: Experimentally verified structural transformations driven by temperature and electric fields are being used to control the physical properties of two-dimensional materials. In this presentation, I will highlight original contributions to the understanding of ferroelectric-paraelectric phase transformations on a family of 2D materials in which the valley degree of freedom is coupled to the direction of ferroelectric polarization [1,2] and will also present contributions to the understanding of magnetoelastic 2D transformations on a novel 2D magnet [3]. In the reminder of the talk, I will discuss two recent models where topology plays a role on materials’ behavior: I will revisit Liang Fu’s original model of a topological crystalline insulator (TCI) to argue for a 2D TCI [4] and will discuss the winding of the Berry curvature dipole on graphene moirés [5]. Time permitting, I will touch upon non-linear optical behavior of TMDCs under biaxial strain [6], and on the effect of atomistic reconstruction on the non-linear optical properties of hexagonal boron nitride moirés [7].
References:
[1] S. Barraza-Lopez, B. M. Fregoso, J. W. Villanova, S. S. P. Parkin, and K. Chang. Rev. Mod. Phys. 93, 011001 (2021)
[2] K Chang, F Küster, B. J. Miller, J.-R. Ji, J. L. Zhang, P. Sessi, S. Barraza-Lopez, and S. P. P. Parkin. Nano Lett. 20, 6590 (2020)
[3] Z. He, S. P. Poudel, S. Stolz, T. Wang, A. Rossi, F. Wang, S.-K. Mo, A. Weber-Bargioni, Z. Qiu, S. Barraza-Lopez, T. Zhu, and M. F. Crommie. Nano Lett. 24, 8535 (2024)
[4] S Barraza-Lopez and GG Naumis. J. Phys.: Condens. Matter 35, 035502 (2023)
[5] A. Huaman and S. Barraza-Lopez (under review)
[6] S. Puri, S. Patel, J. L. Cabellos, L. E. Rosas-Hernandez, B. Reynolds, H. Churchill, S. Barraza-Lopez, B. Mendoza, and H. Nakamura. Nano Lett. 24, 13061 (2024)
[7] L. E. Rosas-Hernandez, J. L. Cabellos, A. Huaman, B. Mendoza, and S. Barraza-Lopez (under review)