Local Probing Of Nuclear Bath Polarization With A Single Electronic Spin

The effect of a polarized nuclear spin bath on the dynamical behavior of a single electronic spin is studied theoretically and experimentally. The polarization of a single nuclear spin modifies the spin-echo signal of its neighboring electronic spin. When the electronic spin is surrounded by a bath of polarized nuclei, the spin-echo signals manifest a characteristic frequency related only to the nuclear spins abundance and their collective polarization. This frequency is proposed as an indicator for the local nuclear bath polarization. We quantify the realistic experimental regimes at which the scheme is efficient. Our proposal has potential applications for quantum sensing schemes, and opens a route for a systematic study of polarized mesoscopical systems.