Bichargon Hall Effect

Abstract

The conventional Hall effect arises from the transverse deflection of mobile electronic charge carriers in conductors. Here, we predict a bosonic charge Hall effect in charge-ordered insulators mediated by bichargons, collective bosonic excitations of charge order carrying quantized electric charges $\pm 2e$. In contrast to conventional electronic carriers, a thermally excited bichargon gas does not support dc electrical conduction in response to an external electric field despite its constituents carrying finite electric charges. We show that a temperature gradient can instead drive a diffusive flow of thermal bichargons, while an out-of-plane magnetic field deflects the oppositely charged bichargons in opposite transverse directions via the Lorentz force, leading to a finite Hall charge current and opposite charge accumulations at the sample edges. Our results broaden the paradigm of charge Hall transport beyond conventional electronic conductors, establishing that a charge Hall response can emerge in an electrically \emph{insulating} system through charged bosonic quasiparticles.