Spectral characterization of noise environments that lead to the decoherence of qubits is critical to developing robust quantum technologies.
While dynamical decoupling offers one of the most successful approaches to characterize noise spectra, it necessitates applying large sequences
of π pulses that increase the complexity and cost of the method. Here, we introduce a noise spectroscopy method that utilizes only the Fourier
transform of free induction decay or spin echo measurements, thus removing the need for the application many π pulses. We show that our method
faithfully recovers the correct noise spectra for a variety of different environments (including 1/f-type noise) and outperforms previous dynamical
decoupling schemes while significantly reducing their experimental overhead. We also discuss the experimental feasibility of our proposal and
demonstrate its robustness in the presence of statistical measurement error. Our method is applicable to a wide range of quantum platforms and
provides a simpler path toward a more accurate spectral characterization of quantum devices, thus offering possibilities for tailored decoherence
mitigation.
Article: https://doi.org/10.1038/s41534-024-00841-w