Margarita Davydova

Feb 16, 2024 | link.aps.org | Margarita Davydova |Patrick Ledwith |Leonid S. Levitov |Qiantan Hong

Electron hydrodynamics gives rise to surprising correlated behaviors in which electrons cooperate to quench dissipation and reduce the electric fields needed to sustain the flow. Such collective free flows are usually expected at the hydrodynamic length scales exceeding the electron-electron scattering mean free path ℓee. Here we predict that in two-dimensional electron gases, the collective free flows actually occur at distances much smaller than ℓee, in a nominally ballistic regime.

Jun 22, 2023 | link.aps.org | Margarita Davydova |Yang Zhang

Abstract Itinerant spin polaron and metallic ferromagnetism are theoretically predicted in the Mott insulator in semiconductor moiré superlattices doped below and above half filling of the narrow moiré band, respectively. The existence of a spin polaron can be directly identified from the kink in the dependence of the charge gap on the magnetic field.

Feb 3, 2023 | link.aps.org | Zhiyu Dong |Leonid S. Levitov |Margarita Davydova |Olumakinde Ogunnaike

Abstract Electron bands in Bernal bilayer graphene flatten out in a transverse electric field, offering a promising platform for correlated electron physics. We discuss the spin/valley isospin magnetism resembling that seen in moiré bands. We predict that the isospin magnetism coexists with momentum-polarized phases occurring via a “flocking transition” in momentum space in which the electron distribution is spontaneously displaced in momentum space relative to the K and K′ valley centers.