LAUSR

Classical spectrum analyzers are widely used but lack microor nanoscale spatial resolution. On the other hand, quantum sensors, capable of working with nanoscale precision, do not provide precise frequency resolution over a wide range of frequencies. Using a single spin in diamond, we present a measurement protocol for quantum probes which enables full signal reconstruction on a nanoscale spatial resolution up to potentially 100 GHz. We achieve 58 nT/ √ Hz amplitude and 0.095 rad/ √ Hz phase sensitivity and a relative uncertainty of 10−12 for a 1.51 GHz signal within 10 s of integration. This technique opens the way to quantum spectrum analysis methods and yields many interesting potential applications.