Vortex Fermi Liquid and Strongly Correlated Quantum Bad Metal

The semiclassical description of two-dimensional metals based on the quasiparticle picture suggests that the resistivity of a 2d metal is universally bounded by the Mott-Ioffe-Regal (MIR) limit, at the order of h/e². If a system remains metallic while its resistivity is beyond the MIR limit, it is referred to as a "bad metal", which challenges our theoretical understanding as the very notion of quasiparticles is invalidated. The description of the system becomes even more challenging when the electrons are strongly correlated. We construct a concrete example of such a strongly correlated bad metal where charged vortices, that serve as dual fermionic degrees of freedom, form a Fermi surface. We demonstrate that at zero and low temperature, the system has a finite resistivity much larger than the MIR limit, and doping away from half-filling generates a small Drude weight in the optical conductivity.