Title: Strongly correlated quantum materials, From Dirac materials and quantum spin liquids to cuprates

Speaker: Dr. Saikat Banerjee, Los Alamos National Laboratory

Abstract: In this pedagogical talk, I will discuss some key features of the correlated quantum materials ranging from ferromagnetic systems, which host Dirac magnonic excitations, and the various aspects of non-magnetic Mott insulators which host quantum spin liquid states, to the appearance of charge-density-wave order in the underdoped cuprates. I will cover three of my recent works as listed here-in-below. In the first part, I will illustrate the role of interactions in the context of Dirac magnons and show that our theory qualitatively accounts for hitherto unexplained anomalies in nearly half-century-old magnetic neutron-scattering data for CrBr3. In the second part, I will discuss the emergence of orbital magnetization in a seemingly different system, such as RuCl3. The latter is a prototypical example of a Kitaev spin liquids, and I will focus on how our theoretical predictions can be utilized to decipher the controversial nature of the quasiparticle characterization in a typical Kitaev spin liquid system. Finally, and if time permits, I will explain the charge-density-wave formation in underdoped cuprates where electron-phonon coupling plays a critical role. Our results suggest that underdoped cuprates cannot be understood in the context of strong electronic correlations alone. The goal is to show the indispensable role of interplay between charge, spin, lattice and orbital degrees of freedom that leads to various novel phases and functionalities.

Phys. Rev. X. 8, 011010 (2018)

arXiv:2208.06887 (Accepted in SciPost Phys.)

Communications Physics 3, 161 (2020)