Probing Electrical Dipolar Fluctuations via Impurity Qubit Relaxometry*

Characterizing the fluctuations of electrical dipoles in materials such as ferroelectrics is a problem relevant to advancing both fundamental physics and device applications. Indeed, such fluctuations, whether they arise in novel phases of matter or two-dimensional memory devices, are traditionally challenging to measure. We propose the use of depolarization dynamics of nearby quantum impurity qubits (e.g. NV centers in diamond) to directly sense these fluctuations with frequency and wave vector resolution. We demonstrate that such resolution can be used to probe the glassy dynamics of relaxor ferroelectrics, to extract critical exponents in para- to ferroelectric phase transitions, and to reconstruct the dispersion of dipolarons in neutral polar liquids.