Tunable pseudo-magnetic fields for polaritons in strained metasurfaces

Abstract

Pseudo-magnetic fields generated in artificially strained lattices have enabled the emulation of exotic phenomena once thought to be exclusive to charged particles. However, to date, they have failed to emulate the tunability of real magnetic fields because they are determined solely by the engineered strain configuration, rendering them fixed by design. Here, we unveil a new universal mechanism to tune pseudo-magnetic fields for polaritons supported by a strained honeycomb metasurface composed of interacting dipole emitters/antennas. Without altering the strain configuration, we show that one can tune the pseudo-magnetic field strength by modifying the surrounding electromagnetic environment via an enclosing cavity waveguide, which modifies the nature of the dipole-dipole interactions. Remarkably, due to the competition between short-range Coulomb interactions and long-range photon-mediated interactions, the pseudo-magnetic field can be entirely switched off at a critical cavity width, without removing the strain. Consequently, by varying only the cavity width, we demonstrate a tunable Lorentz-like force that can be switched on/off and a collapse and revival of polariton Landau levels. Unlocking this tunable pseudo-magnetism poses new intriguing questions beyond the paradigm of conventional tight-binding physics.