PIRSA:22050039

Superconductivity, charge density wave, and supersolidity in flat bands with tunable quantum metric

Hofmann, J. (2022). Superconductivity, charge density wave, and supersolidity in flat bands with tunable quantum metric. Perimeter Institute. https://pirsa.org/22050039

Hofmann, Johannes. Superconductivity, charge density wave, and supersolidity in flat bands with tunable quantum metric. Perimeter Institute, May. 18, 2022, https://pirsa.org/22050039 

          @misc{ pirsa_PIRSA:22050039,
            doi = {10.48660/22050039},
            url = {https://pirsa.org/22050039},
            author = {Hofmann, Johannes},
            keywords = {Condensed Matter},
            language = {en},
            title = {Superconductivity, charge density wave, and supersolidity in flat bands with tunable quantum metric},
            publisher = {Perimeter Institute},
            year = {2022},
            month = {may},
            note = {PIRSA:22050039 see, \url{https://pirsa.org}}
          }

Johannes Hofmann

Talk number
PIRSA:22050039
Collection
Talk Type
Subject
Abstract
Predicting the fate of an interacting system in the limit where the electronic bandwidth is quenched is often highly non-trivial. The complex interplay between interactions and quantum fluctuations driven by the band geometry can drive a competition between various ground states, such as charge density wave order and superconductivity. In this work, we study an electronic model of topologically-trivial flat bands with a continuously tunable Fubini-Study metric in the presence of on-site attraction and nearest-neighbor repulsion, using numerically exact quantum Monte Carlo simulations. By varying the electron filling and the spatial extent of the localized flat-band Wannier wavefunctions, we obtain a number of intertwined orders. These include a phase with coexisting charge density wave order and superconductivity, i.e., a supersolid. In spite of the non-perturbative nature of the problem, we identify an analytically tractable limit associated with a `small' spatial extent of the Wannier functions, and derive a low-energy effective Hamiltonian that can well describe our numerical results.