Natural anomalous cyclotron response in a hydrodynamic local quantum critical metal in a periodic potential

We study DC magnetotransport in a quantum critical metal in the presence of a lattice. In the regime where the transport is hydrodynamical the interplay of the Lorentz force and the lattice gives rise to a natural anomalous contribution to the cyclotron frequency that changes it from its canonical charge-to-mass ratio. The size of this effect is universal as it is determined only by thermodynamic quantities. Remarkably the Drude weight changes in such a way that to first subleading order in the lattice strength the Hall resistivity and Hall coefficient do not change, though the Hall angle does change. We confirm our results with numerical simulations in a holographic model of a strange metal. For weak lattice strength these hydrodynamic effects are shown to be present. The numerical simulations also suggest that strong lattice effects beyond a hydrodynamic regime may provide a resolution to the experimentally observed anomalous Hall response of cuprate strange metals.