Electrical signatures of chiral quantum spin liquids

Quantum spin liquid (QSL) has currently become an interesting topic in interacting spin systems which nevertheless do not order magnetically down to the lowest experimentally accessible temperature. Since its first proposal as a bosonic counterpart of fractional quantum Hall effect in a triangular lattice, the corresponding lattice has always remained a center of attention as a potential set-up to realize this state, however, conclusive evidence is still lacking. Motivated by the recent surge of theoretical and experimental interests in these systems, here, we revisit this state of a half-filled Hubbard model on the triangular lattice by focusing on its concomitant electrical signatures. We discuss the localized orbital currents utilizing mean-field parton description. Our analytical predictions are further supported by an unbiased density-matrix renormalization group (DMRG) calculation on the Hubbard model in an intermediate coupling regime. Our results show that the chiral QSL phase has a clear electromagnetic response even in a Mott insulator, which can facilitate the experimental detection of this long-sought-after phase.