Exotic Phases and Unusual Transport Properties in Moiré Materials
Unmesh Ghorai
Department of Theoretical Physics, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
In the first part of my talk, I will discuss Moire systems and recent advancements in this field. Specifically, I will talk about twisted double bilayer graphene, which is a compensated semimetal near the charge neutrality point (CNP) with the presence of small electron and hole pockets in its band structure. We will show that strong Coulomb attraction between the electrons and holes can lead to the formation of excitons which has interesting implications for low-temperature transport in the system as a function of carrier density and temperature. The fluctuations of the Landau damped order parameter in the quantum critical metal lead to the non-Fermi liquid behavior which can explain the sublinear temperature dependence of the resistance near the CNP.
In the second part, I will talk about the origin of superconductivity in twisted bilayer graphene using Hartree-Fock bands, where the preliminary data shows interesting anomalies in the relevant densities.
