  While geometrically frustrated quantum magnets are known for a variety of
exotic spin states that are of great interests of understanding emergent
phenomena as well as enabling revolutionary quantum technologies, most of them
are necessarily good insulators which are difficult to be integrated with
modern electrical circuit that relies on moving charge carriers. The grand
challenge of converting fluctuations and excitations of frustrated moments into
electronic responses is finding ways to introduce charge carriers that interact
with the localized spins without destroying the spin states. Here, we show
that, by designing a Bi2Ir2O7/Dy2Ti2O7 heterostructure, the breaking of the
spin ice rule in insulating Dy2Ti2O7 can lead to a charge response in the
Bi2Ir2O7 conducting layer that can be detected as anomalous magnetoresistance.
These results demonstrate a novel and feasible interfacial approach for
electronically probing exotic spin states in insulating magnets, laying out a
blueprint for the metallization of frustrated quantum magnets.
